At work, I build for the corporate standard, which currently includes 3 desktop browsers and two mobile ones - at specific versions. I am happy about that environment.
However, when building for the internet, I usually tend to support IE11+ era browsers (using caniuse.com), because out of habit, many people still open their IE on Win10. All browsers of this time are very capable and I can use many modern features. I really hope, though, that the usage shifts more towards more current browsers, especially away from IE :)