I can offer a perspective as both a bedwetting child and the mother of two late bed wetting DDs (now both dry!)
The alarms never worked for me or for DD’s. They just woke everyone up.
Luckily when I was a child in the 80s my parents were easy going about my bed wetting and just gave me the option of wearing “child size” nappies (basically just huge disposable baby nappies) that we’re available from Chemists in those days. There were no Pull-Ups or DryNites then.
We did try going without every few months and it never worked. We occasionally tried the alarms (which were available then) but they never worked either.
I realise now I was lucky because I now know many kids were still punished or shamed for bed wetting back then.
I eventually outgrew it when I was in double digits (which was just as well as the child size nappies barely still fitted).
With my own two DD’s I provided Pull-Ups and later DryNites for as long as they were needed. I did the same as my parents and (with DD’s cooperation) tried without periodically and also tried the alarm method.
In the end, by which time my eldest DD was also in double digits and still in DryNites, someone suggested to me that the problem might be drinking cordials, especially blackcurrent.
I was a Ribena junkie as a kid and both DDs had “no added sugar” cordials throughout their childhood.
We tried for a week with just milk and water (and later pure fruit juices) and the bed wetting stopped almost overnight.
I was genuinely gobsmacked and did not want to think about how much money I might have saved (and my parents might have saved!) if we had known earlier.
If your son likes cordials (fruit shoots are the worst) then maybe try going to water and milk for a week, just to see what happens.
It might be your miracle cure too, and best of all it’s free!
Got to be worth a go- it worked for my two.