[chmod775]

It appears website developers desperately want to return to a world where browsers actively pretend to be another browser*.

Want to check for DBSC? Enjoy not knowing whether the browser vendor decided to just roll a simple software implementation.

Nothing good comes from browser detection over feature detection anyways. It's time to do away with user-agents and other overt identifying markers, and if we're still not in a better place, aggressively start stubbing features.

* to some degree they still are. Firefox still ships with an user-agent override list for certain websites that have outdated user-agent sniffing for feature detection (and other fixes in about:compat).

[pjmlp]

You mean the same that gave Chrome its market share, by adopting ChromeOS features, and shipping Electron apps?

[edoceo]

What is the process to aggressively stub features? Does that mean pushing patches to Firefox and/or Ladybird and/or Servo?

[JoeAltmaier]

And yet, claiming support for a feature doesn't tell all. Different implementations can have subtle differences. Knowing the browser and version can allow a client to survive that.

[chmod775]

Yes, that is the price developers will have to pay. Development will be harder, but users are going to prefer somewhat broken sites over being outright refused entry.

At the end of the day user-preference is what dictates which browser is used and how it is configured. Developers will have to deal with what users choose to do on their end.

You can only patronize people for so long before they look for a way around silly restrictions. Trying to keep someone safe by putting up walls, whether the threat is real or imaginary, is pointless when it is in the user's power to trivially defeat those walls - and when extension and browser developers are going to line up to sell them demolition tools (see ad blocking).

Advice is going to go much further than roadblocks, long term.