I honestly think it's every dev's responsibility to make their game well optimized for lower end hardware and to make it look clean without a huge amount of visual clutter so players/attacks etc are very easy to distinguish. If these factors are satisfied then I think it's ok to be more restrictive with settings but I still think allowing people to have more customisable settings to their preference is always a good thing. High level players are almost always going to set the graphics to low to gain both of these advantages whatever you do, making the important settings easy to access and making the defaults non-garbage is probably the most important part.
I'm not happy with the way either TF2 or Overwatch does this, but as TF2 at least doesn't restrict most of its options I think the settings it has are far far better, even if these settings are often hard to find.
Valve would be much better off overhauling the default TF2 experience as opposed to changing the experience for players already invested in the game. Disallowing graphics settings has a negative impact on players who were already playing the game for long periods of time and has very little positive impact on the skill gap as new players are likely to be much worse anyway. Instead this could be addressed by making the default graphical and net settings non garbage, and adding in a decent tutorial and easy to navigate menus. This game is free so many of the people who play it will be children who don't have money to buy games- they especially are going to need the help in working out what the fuck is going on. Penalising players who already play makes no sense.