It does amuse me when people ascribe incredible, complex, "conspiracies against the people" ideas when it comes things like EV's and "keeping hydrogen secret until the EV market is saturated"! The idea that all those companies, from all those countries could agree to sit on something when there would be a commercial advantage to being first to market with something new is hilarious. That is not to say that car companies can't agree and won't lobby governments - they will! But the only thing they can agree on is "we don't need any changes" - emissions legislation: "we don't need it", lead free petrol: "we don't need it". CO2 limits: we don't need it". The only variation, another favourite, is "it can't be done". They are businesses, they don't want to spend money or engineering resource on anything that the customer doesn't want to pay for. And customers are not reasonable beings! They do (in the main!) want cars to be cleaner but they don't think the cost of cars should increase because of the kit (and the work) required.
As far as "they diddled us on diesel is concerned" - nonsense! The GOVERNMENT encouraged the sale of diesels because they wanted to hit CO2 targets - and politicians are not good at holding more than one thing in their heads at once so it's "Diesels are good on CO2, right?", "well, yes, but it's not as simple as that, take particulate emissions for example...", "yes,yes, but they are good on CO2, right?" CO2 is the flavour of the month and that's that - politicians want simple, easy answers to difficult, very complicated questions - nothing new there. And, don't forget, the diesel bubble mentioned on this board is a UK only thing - diesel car sales vary in different markets according to governmental policy/taxation. The car companies were not wild about it - a diesel car costs more to make but it's very hard to sell them for enough of a premium to cover the higher costs.... But if the customers are voting with their cheque books because the government is urging them that way - what will the car companies do - sell them what they want - what else could they do?
EV's - the car industry has been dragged kicking and screaming into the manufacture of EV's and have only done so because deadlines have been imposed be it 2030, 2035, 2050. The car companies know the problems and the issues but they have been put in a position where they make EV's or they stop being car companies - hardly a conspiracy on their part. And they have no time left! The development of a new engine based on existing technology and manufacturing processes takes years in automotive powertrain terms 2030 is tomorrow, 2035 is tomorrow evening.... The governments say "no more piston engined cars (even if they run on hydrogen) after 2030 so the car companies have no choice but to believe them - and if, as seems increasingly likely, the governments have to back down - well, at least they will all be in the same boat. Meanwhile the costs of developing their new EV products is HUMUNGOUS not only is the powertrain new, the gearboxes (many EV's still need them) are different, the vehicle structure is different, the crash behaviour is different, the heating and ventilation is different - no more hot water from the engine, no more slapping an aircon compressor on the side, the electrics generally are different, the brakes are different I could go on.... So there is a lot to do and a lot of cost - when it comes to manufacture the processes are, in many areas different, factory layouts are different - again it goes on. And it's not just the cost - if they WANTED to continue development of the good old combustion engine as well - the engineers are just not available - you fancy trying to recruit young engineers into your piston engine department now? Good luck with that!
Hydrogen - I can remember a Hillman Imp with a sodding great welding set sized bottle of hydrogen diagonally across the passenger compartment running round the then School of Automotive Studies (so I can honestly say I am ex-SAS

) in 1973 - but it's not easy.... Storage is a big problem - to carry just a couple of kilos of hydrogen you need a "tank" weighing about 25 times that. It's the smallest molecule - it leaks through the tiniest gap, before you know where you are, the car you parked full yesterday is empty today. Then there is distributing it - same issues - and if the government isn't interested because "EV's don't have the NOx drawback do they?", "Well, no but it's not quite that sim...", "Yeah, yeah but we can just push EV's". I personally think hydrogen has great potential as a PART of the solution but let's not kid ourselves it's easy (you could buy a hydrogen fuelled BMW a few years ago - but they were not popular)
Why do I know this? I was part of it, an engine engineer for my entire career. I remember lead free - it caused me so much pain - we had to develop a new solution for an engine which didn't have room for conventional seat inserts and because we had resisted for so long there wasn't a lot of time so it was under-developed and risky - as it happened, it worked.... I still refer to working on an EV as "going to the dark side". But to suggest that those working in the auto industry could develop and sustain a conspiracy along the lines suggested is deeply comical.