Julio - absolutely. My last employer had to be able to cope with tax systems from multiple nations as well as from all US States. That meant a positively evil amount of tax regression to make sure nothing broke.
Once the framework was in place, the tax regression took almost a month to put together, and had a run-time of 12 - 16 hours depending on what else was happening on the network at the time (we usually ran it over the weekend). The thing couldn’t be unit tested (old Pascal code grandfathered into Object Pascal, which in turn was grandfathered into Delphi), so the UI level automation was all we had.
Even when increasing network load and other problems forced the regression suite to be split so it could run overnight, the old warhorse kept chugging on, and kept on notifying us of any changes that messed with tax calculations.
If we’d had to verify those calculations manually, it would have driven the entire team insane - there were thousands of transactions that calculated every way of managing sales tax imaginable (and quite a few that shouldn’t be) including with and without foreign currency translations, currencies with different numbers of decimal places, different rounding rules… you name it.
There are other forms of “test automation” that aren’t quite as obvious. One that I engage in regularly at my current place is in the form of running two queries and exporting the output to text files. Then I run a file compare against the two. That’s it - but the queries mean I don’t have to deal with manually checking that every piece of data in the file was correctly imported because the query covers that for me.
I have a number of other database queries I use with other tools to make some of the tests I need to do easier. It’s not full test automation, but it’s certainly using automated tools to make my life easier.
Then there’s the CI pipeline I’ve set up to run my (currently minimal proof of concept) test automation suite. I arrive at work to an email telling me how my automation ran. If anything failed, I check it and fix whatever it was - most often something I can’t control although I have caught bugs with it.
Any level of automation can be helpful. How much you need and what you can do depends a lot on where you are, what you’re working with, and what the rest of the team is doing.