As someone who enjoyed FPS games like Halo, Dark Forces, and Republic Commando, Fallout 3 and NV were just fine. Granted, I was more reliant on VATS in NV, but FO3 was fun enough with all the shooting. If there's anything that was rusty, it was the isometric gameplay of the old Fallout games, which was falling out of fashion at the time, while the FPS/RPG hybrids were rising in prominence, like Oblivion and Mass Effect. And the fact that normies ate up Fallout 3 as if it was ice cream in the middle of summer showed that it was a good-enough game that people wanted more of.
And in terms of plotline? Fallout's main plots were, outside of New Vegas, mostly bland. I say this as a person who came into the franchise through New Vegas: FO3's plot was serviceable at best, barely average, but I was highly disappointed by the plots of FO1 and FO2, as if the bad guys there had to be stupidly evil for you to oppose them. You have a mutant overlord who blows his brains out because his mutants are sterile, despite the fact that he already has a steady supply of human cultists/cattle who blindly follow him, and whom he can easily breed for future super mutant candidates. Then you have a stupid evil version of the government that went full Nazi because they wanted to bitch about how stupid patriotism is and hammer in a racism parallel with the government being obsessed with racial purity, when really, 1950s Anti-Communist America was more obsessed with ideology, since they fully supported African warlords and Latino dictators who were anti-communist.
At least I can understand Fallout 3's Enclave, which is a remnant of the US government going warlord and trying to recruit wastelanders to the cause with water, and their leader wants you dead because your dad tried to kill him. Not the most clever of enemies, but hey, at least that's something I can understand. They have a good-enough justification for existing, and I have a good-enough justification for putting them six feet under. That's far more than what the first two games did, where the villains might as well leap from the pages of some comic written as an over-the-top satire rather than a realistic post-apocalyptic scenario.
And are the previous games any better? Seriously, it's not like this series was KOTOR 2 levels of brilliant prior to Bethesda buying it. It was just another isometric game series with an OK setting and aesthetic, whose writers came from the same school of thinking as the Watchmen/Warhammer 40K writers who wanted to whine about how bad the Reagan/Thatcher-era anti-communist governments were. Then their owners drove the franchise into the dirt with some poor decisions, and another game studio snapped up the series.
The point of FNV WAS to contrast fascism with capitalism and democracy. So no shit, they pit Henry Ford against Hitler. Except FNV's version of Hitler didn't have a master race philosophy and was actually all for race-mixing so as to erase any other loyalties outside of the state. You have an aloof capitalist landlord who was OK with whatever you did so long as you paid your dues, and you have a fascist warlord who sacrifices freedom for security, and you have a well-meaning democracy with bureaucratic shits. That's a lot better than anything Fallouts 1-3 offered.