My short answer:

Should I switch to Wayland?

Yes.

Applications that don’t cope with wayland still work via Xwayland. Go ahead.

You should, I think. You don’t have Nvidia GPU, so you can avoid almost bugs and better performance.

Advantages:

1. Better performance. e.g. for Firefox, @lilydjwg got double performance in wayland.
2. Better multi-screen with multi-DPI support.
3. Better maintaince. Many DE has put more and more to wayland. And many new features will only be implemented in wayland. (That’s because implementing many new features will be difficult or even impossible in X11 old software architecture, as KWin developers said.)

Disadvantages:

1. Some missing feature, such as remote desktop.
2. Many bugs when you use Nvidia GPU.
3. None of the compositors except KWin and Hyprland can use input methods with electron.

I don’t know which DE/WM you use. If you use Plasma/GNOME, migration is simple, just switch in SDDM/GDM. If you use i3, you can try sway, it’s compatible with i3 config. If you use others, you can try hyprland or wayfire. Wayfire has fantastic animations.

I switch to wayland because I buy a new screen with different DPI… But when I switched, I found I got better performance and video hardware acceleration in Firefox (this feature was introduced to Firefox Wayland first).

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Plasma is slick as butter on Wayland.

in my experience wayland is faster to log in and less input lag, problems are things like discord that don’t implement screen record, but it work on the browser, and sometimes i need to find replacement for some apps that work on wayland(like xdotool to simulate mouse etc) i use fedora so wayland is default

You should, and you will :) X11 is legacy, and is going to die. The only question is whether you're going to try and hold on to a broken system riddled with security vulnerabilities for as long as possible until you're forced to switch, or whether you're just going to enable what is mostly already the default stack on most desktop Linux systems anyway.

If it ain’t broken don’t fix it.

What are the advantages of Wayland?

More modern and in some cases better performance (as if Xorg performance were bad … but hey)

What are the disadvantages?

Basically none of your current software works out of the box (you’ll need a special Xorg implementation that works with your Wayland implementation in order to run non-Wayland applications). Most applications are specific to your Wayland implementation instead of a general application that runs in all environments.

why have/haven’t you made the switch?

I did not find one single floating WM that is as good as Openbox for Xorg. Also: Screen recording with OBS is problematic in some constellations.

The biggest Sin by far of Wayland is making users think about the graphics stack. Does this feature or this app support Wayland or X? Does this Compositor support this GPU? Does this particular environment support this mixture of displays with this DPI? Do I need to set a particular env variable or change a setting to force this app to start in Wayland mode because under X11 its scaled funky. What works in each environment? What doesn’t work between environments?

Well before you reach the end of this flow chart you have lost virtually all of your users. This transition has single-handedly set the Linux desktop back by 20 years in terms of supporting more users whose level of interest in configuration is limited to clicking a control next to their monitor and making things bigger or smaller.

A saner design would have handled scaling correctly from the start and would have had a permissive mode which just made everything from the users perspective work while progressively adding a correct UI to provide features like global hotkeys, screen sharing, only to those apps users had authorized like android. If it wasn’t a such a clusterfuck to use it would have had orders of magnitude more users much earlier in the development phase and perhaps attracted more development interest as well.