I don't particularly like writing unit tests either. However, one goal I set myself decades ago is less than one bug per kloc delivered. (I don't always achieve that.) If you seriously attempt to do that over many years unit tests become unavoidable. For me that path to unavoidable looked like this:

1. Decide that was the goal. Start measuring. Who knows, maybe I have to do nothing.

2. Discover that I seriously underestimated the number of bugs I produce. No one is available to review my code, changing languages (to something with a stronger type system) was out of the question. Only option appears to be methodical testing of every line of code.

3. Print (on dead trees - this was decades ago) all my code. Manually test all of it, running a highlighter down the listing. Continue to the entire code listing has a solid line of code down the left. It worked! Bugs per delivered lines of code dropped off a cliff. But geezz it took a loooong time, longer than writing the code. Finding an input sequence the exercised some code was surprisingly hard. And it was boring. Still success - and people who used it immediately noticed the improvement in quality and commented.

4. Then new features have to be added. Does this mean I have to test it all again? Surely not - I'll just test the bits I changed. Result: bugs per line of code rapidly start to ramp up again.

5. So I test everything again. That works, but it's horribly inefficient. I can spend days releasing a few line change. I can't get small changes anything like a reasonable time frame.

6. The solution is obvious to a programmer: automate your work, which in this case translates to writing code to do the tests. So I write unit tests for new code. It ends up being slower than doing manual tests :( Code size doubles. It works in keeping the bug count down, but can I afford to keep doing this time wise?

7. Then I add features to new code with unit tests. Initially this is painful - I move at perhaps 1/2 the speed because now I have to change at least twice the amount of code (actual and unit-test). Still, it's success bug count wise, and running unit tests is much, much faster than manually testing.

8. Keep doing this, notice that despite me having to change twice the lines of code (actual code and tests) when I'm adding new features I'm producing more debugged lines of code than before. Even more interesting, I'm fearlessly making much larger changes now. Turns out I'm using the unit tests as guard rails. I no longer minimise my changes to reduce the odds of introducing a bug.

9. Finally, notice that unit testing has changed the way I write code. And it's for the better. Code that's easy to test is also easy to understand. For example, it's much easier to test a pure function than something with side effects, so you minimise side effects as much as possible. You make your interfaces (which are the thing you focus your testing on) as small as possible. Testing deep inside a complex module is difficult and the torturous unit test code you have to write to do that is hard to understand. So you split things into smaller modules, each of which has those clean interfaces, to give your tests greater visibility. Turns out writing code so unit tests can understand it is oddly similar to writing code so that humans can easily understand it.

So it turns out unit testing is a win in every way, when done well. Well, except for the "it's boring" bit. (Numerous comments here hint at copilot being a real help.)

But writing code that's amenable to unit tests isn't something you do naturally. Fortunately just getting practice at writing unit tests is enough to teach the skill. Sadly, that takes time and frustration. While you learn your productivity will drop for a while. And worse, when writing new code adding unit tests is always slower than the old way. The pay back only comes when you later make changes.