At the final table of a tournament with about 800 players, the average stack will be about 100 times the starting stack. Even without blinds, you would need to double up 6-7 times to get there. This means

You should accept that you will not make very many final tables. No one can ensure making it deep into a MTT.

If you want to make the final table, you need to gain a lot of chips. Do not overvalue survival. Be willing to risk busting out to make the right plays.
It sounds like when you care about a tournament, you notice that you bust out often. The same happens when you don't care about the tournament, but you don't pay as much attention. Also, you might feel more free to make good plays which risk busting out in tournaments where you don't feel you have as much invested. Of course, those fields may also be softer so that it is easier to do well.