5 days extra holiday for my 10th year anniversary, but then I go back to 25

I’ve been with my company for 10 years now. For the 10th anniversary, they award the staff extra 5 days of paid holiday, so 30 days in total. I recently found out that it is only a one off benefit, so in my 11th year I would be going back to 25 days. Am I reasonable thinking that it is actually really poor of them to revert it back to 25? My thinking is, since I’ve been a loyal employee for 10 years, great, I’m getting 5 days extra, but then as I continue, I basically revert back to the same benefits as someone who’s been with them for 5-9 years. I see no real benefit of staying longer than 10 years? Has anyone heard of this practice before - I’ve mostly come across benefits where employees gain days with years of service, so the benefit they are offering me seems really poor?

What’s important to add is that because of the state of our industry, they haven’t been the best in retaining their employees, giving us any pay rises, any other benefits at the moment, or any annual bonuses. My last salary review was 1 year ago (they bumped me by 2k), after I was literally fighting for it for ages, having to prove to them that I deserved it. I have no benefits like dental, medical, gym, or whatever else people have nowadays. So my thinking is that, if they revert me back to 25 days, I’d be like any other employee, with no real benefits anymore. Crazy to think my loyalty is only rewarded with a one off holiday bump. They aren’t giving any rises any time soon either so with the inflation and prices I feel like I’ve been getting a pay cut.

Am I being unreasonable? How can I fight/convince them to keep the extra 5 days of my allowance? Unfortunately I can’t just quit and move elsewhere because there are no jobs in my industry at the moment so I should stick to what I have… But I feel like they don’t do anything to keep me there, and I feel they should at least let me have these 5 days to keep me happy and retain me as a loyal employee. At least that would definitely make me happier and I’d consider staying if I had an offer from someone else.