Please more details about the practical benefits because I kind of see in general why it can be good but there is still certain lack of the real practical demonstrations from those who use it daily.
I don't recommend emacs because the vast majority of packages have "Lisp Incompletion Syndrome"--they get the easy 80% right and leave you to get bitten by the difficult 20%.
lsp-mode and tramp still have bad Heisenbug interactions even after you get the correct incantations to make them not crash. Other packages are similar.
There are a few very core packages that work well. Everything else is in sufficient disrepair that you will have to pick the broken pieces up off the floor at fairly regular intervals.
Personally I kind of view it like having a custom mechanical keyboard. Why not invest some time and money into making your tools more ergonomic and enjoyable? Yeah any keyboard will work, and any text editor will edit documents.
Text-editing aside, magit and org-mode are particularly nice in Emacs. Plus there's just something comforting knowing that Emacs will always be there for me, just the way I set it up.
I did that for many years. After switching from one machine to the next, one operating system to the next, one IDE to the next, everything constantly changing, year after year - I found myself in a job where I had to reinstall the OS and everything on it from scratch, every two weeks, for a year, because... well. Because! By the time that was over, I had given up customizing much of anything at all, and that has been working out all right ever since.
(If I had already been an Emacs fan, I suppose I could have found some way to forcibly bodge things together and use my preferred editor regardless: but I'm afraid it's never appealed to me.)
Because unless you use just one system daily or even weekly, customizations are nothing an annoyance since it’s unlikely you can clone every customization across every system you use daily.
But you can, even for physically distinct machines: just package-up your emacs/environment/shell/etc profile into a bash-bunny USB stick, such that the bunny uses its keyboard emulation to type-out and run the commands that load your profile into your current machine.
I would recommend a Raspberry Pico as a fake keyboard, it has 2MB of storage. But that all falls apart when you are not allowed your own USB devices...
In a world of corporate built software that may or may not exist in a few years, Emacs is an investment for life. It's the last editor, or whatever you use it for, that you'll ever need.
If the main maintainer is a large company, they can decide to shift focus at any point and abandon the project, which puts its existence in jeopardy. (GNU) Emacs and Vim have been around for decades, and they're pretty much guaranteed to be around for many decades to come. As far as long-term investments go, learning and using these is the safest choice you can make.