I have no idea where "worse" came from, I'm assuming I was typing a post somewhere else and put a word from there here
Biggest problem of 3 for me (aside from the endless metro tunnels) was how trashed it was, Fallout is a series set decidedly after the apocalypse.
It's 80 or so years after the event in the original and life has already begun to move on. In fallout 3 it's
TWO HUNDRED YEARS since the apocalypse but it looks like it happened yesterday in the majority of the game's areas.
What's even more grating is that the exceptions are the stupid as strawberry float bomb town and places which basically got missed by the bombs; the game fails to convey any real sense that the humans have moved on since then; they really didn't do enough with vault 101 to create a contrast between a society that's lived in
mostly isolation since the nukes and the outside world which has developed on its own.
In regards to exploration I was genuinely put off by all those massive piles of rubble blocking off most of the overground (to force loading screens between areas), felt like the invisible walls of games from an earlier era except you could now see them. Most of my issues with Fallout 3 are things that only really stuck out to me after playing when I reflected on the game but those blockages straight up killed my immersion when playing.
NV was much better in that regard by gating you in slightly more subtle ways and by having non-scaled enemies off the beaten path to brutalise you if you tried to go to end game areas at early levels (this was especially good because the player could actually make it through these areas with enough skill/planning/trial and error/luck)