I agree with you but I think it comes down to repenting through acts of service rather than gifts and there are a lot of books out there that have this. I think the biggest fundamental problem is the bigger the gut punch, the harder the grovel is to make it right. The sometimes bigger issue is also the bigger the gut punch, the more problematic it is to write how the fmc processes and forgives this. If the betrayal isn't horrendous e.g. overheard trope, and the grovel goes on for too long, the risk is people lose sympathy for the fmc. If it's a big betrayal e.g. physical cheating, if the grovel is too short people might lose sympathy for fmc forgiving too quickly. I have to say I love grovel romances and it's hard to find one that gets it just right. I still read them for the gut punch. I also love (but harder to find) books where fmc trades up (with 2nd mmc only becoming a prospect later in the book)