Are you suggesting helium as an alternative to a hydrogen future? BTW, the NY Times was touting hydrogen produced by electrolysis fueled by nuclear power, when it looked like we were running out of petroleum, fifty years ago.
No. I’m not suggesting anything.
Helium and hydrogen are both very light. Helium is not flammable and hydrogen is explosive.
Helium is an excellent alternative for blimps etc. But not for an internal combustion engine.