Getting meta alloy is certainly harder now than ever before
No, getting meta alloy is certainly NOT harder than it was before.
Robigo was nerfed, demand across systems nerfed trade and mining because selling is stupid hard now.
Robigo was not exactly nerfed, it can still provide 100 millions per hour with the correct Python build
The prices you can sell at are nerfed.
Prices for precious minerals were indeed nerfed along with generic mining nerfing that happened post carriers release.
You are missing a lot of things. (combat pays a lot more now, thargoids too, massacre missions are a thing, 25k per ton trading is also a thing, the random cg where people can get billions, etc)
How many hours is it now to unlock the engineers?
Unlocking engineers takes the same as before, nothing changed.
How many hours now to be able to Thargoid hunt?
To be able to get into thargoid hunting depends on how skilled you are at flying and shooting and, in general, at the game.
Any other reasons why the population is dying?
Is it dying? According to the steam charts, the playing population is about the same as it was in 2016, 2019... If Elite was dying back then, then yea it's dying now too.
However, it's an old niche nerdy game with a steep learning curve - it was never as popular as the mainstream games and will never be
Now, do you actually play the game? yes/no?
If yes, have you quit after you decided that you dont like the game, then came back and now you're starting to remember why you left last time?