It's also in direct conflict with the previous statement. If a large contingent of people are buying and playing these games, then there does not need to be "a certain level of graphical fidelity these developers have to achieve if they want to be taken seriously."

For me there is "a certain level of graphical fidelity" past which the game looks like trash. That is looking worse than the games of the era it takes inspiration from.

It is a combo of indie devs not understanding the way oldschool graphics worked and going "lets just add more polygon jitter and reduce the resolution further lmao because that's how PS1 was amirite", and taking bad along with the good – like super low drawing distance in some of the recent "PS1-like" titles.
I've seen a few games that are in 120/140p – resolution lower than that of a GameBoy, and low-poly that would be considered sub-par even in '96.
Bonus negative points for clashing levels of fidelity between different aspects of the image, like putting noticeably higher-poly objects along with lower-poly ones, significantly inconsistent levels of detail between areas etc.

The other thing some indies are guilty of is using "oldschool" visuals as an attempt at putting in less effort, which invariably looks like shit because good visuals take effort regardless of technical fidelity.