If your day-to-day tasks involve "modern web" apps, sure. Too many modern websites are simply unusable on too many older systems (without jumping through hoops that require a "modern" system to act as a bridge, which kind of defeats the purpose.)
But there are *PLENTY* of day-to-day tasks that don't require anything modern. If you spend most of your day writing documents in Microsoft Word - you can use Microsoft Word 5.0 from 1991 on a Macintosh Plus! Modern versions of Word can still read documents saved from Word 5.0 just fine. (Although Word 5.0 can't read modern documents.) Heck, I write Markdown documents regularly, and that doesn't need graphical editing, so I can use TextEdit/SimpleText/TeachText/Windows Notepad/DOS EDIT/emacs/vi to write my documents no problem.
If your job, like mine, involves a lot of "text mode command line" work remotely to servers, that can be accomplished by anything that can act as a serial terminal with a bridge Linux/UNIX box (that can itself be ancient, since newer ssh versions have been ported to basically every architecture, including A/UX.) The biggest annoyance of using an old system is that I'm used to 100+ columns, 50+ lines in my terminal window now, and I go through log messages where a single log message could overwhelm a 40x25 display.
For my day-to-day work, the biggest barrier is that I am on a lot of Zoom/Google Meet/WebEx calls every day (yes, a mix of all three,) including video. There is no way to join a WebEx video call, with video, on an older system. And I demo my company's web-based product on these calls - can't do screen sharing on older systems, even if I could get our website to load on older browsers. (On a lark, I did hack a demo copy of our product to remove SSL, and the login screen loaded on Microsoft Internet Explorer 5 - I filed a bug with our UI designer complaining that it didn't render properly. He laughed.)