The game was designed for people to have played the first one first. I think the difficulty curve works best if you consider Silksong as a direct continuation of the first game, picking off where the main story left off rather than the extra challenges they added through updates like godhome.
The only 2 enemies vulnerable to a single type of attack are DLC and you have your full arsenal by then.
I agree that the game is a bit weird during the second and third missions due to the limited tools you are given, but I think you might be exaggerating how the weaknesses work a bit.
I honestly prefer Fallout 3 over New Vegas slightly. It has better level design, vaults, and the world feel more alive.
I just tend to stay quiet about it because people get really toxic when you say anything that could be seen as a criticism of New Vegas.