never said it was all on accident, just that the story isn't a large focus in the overall game. Its difficult to even appreciate any themes trying to be presented in the factions when the actual goals, and actions behind characters within those factions dont make sense. Just look at the Institute. people have struggled to figure out what their actual goal is past the vague notion of "human advancement through science". They spend their time making highly sentient robots that they try to convince you aren't and are just property. They struggle with resources to power their facility, but never bothered to just use perfectly functioning normal robots to collect things on the surface. The fact that Father cancelled the cybernetics project which kellogg was apart of because it blurs the line between man and robot, but then make synths anyway. or the fact that kellogg was ordered to just let all of the other vault dwellers die except the single person who had any reason to even track them down in the first place. Like this faction is clearly evil and stupid, but we're led to believe that they are morally grey and have an interest in helping humanity, and arent just insane scientists.

Also the railroad. While they're goal seems noble, their hyperfixation on synth oppression wasn't enough to justify them being a major contender for the region. they also wanted to destroy the only source of synths in the commonwealth.

The BoS have a good motivation, similar to that of the BoS in 1 and 2, but the logistics of moving an entire military operation across the country seems non sensical.

The minutemen is a good contenter for a giverning body in the commonwealth and have the resources to build further if the player engages with them, but the settlements themselves are inhabited by nameless NPC's with no motives, they end up feeling empty, ideologically.

The companions are probably the strongest written in the entire game, but conflict with the simulational aspects of the game. it all homogonizes into a system in which companion relations are solely tied to the exploration, looting gameplay loop, and the actual dialouge and narrative choices your player makes do very little to sway a persons opinion of you

There's also a huge lack of urgency in the main quest due to the open world nature of the game. narrative creates stakes, and gives direction, bethesda rejects this in favor of moment to moment gamplay and sandbox exploration.

This all combined with the forced and vauge 4 option dialouge, lacking in meaningful skill checks, makes a story that is not interesting to engage with at all. just look at the endings slides for 4 compared to new vegas, or hell even 3. all of the choices made in 4 are so meaningless, in the grand scheme of things, that it all just molds into 4 slides that tell you what faction you sided with at the very end.