Part of the tenancy agreement says the kitchen doesn't need to be repaired/replaced until over twenty years, and we can't even do it ourselves, especially as the doors are different sizes. Other photos of the kitchen show it falling apart more, but I tried to send the better pictures.
Is that the point of your post, you want a new kitchen?
The landlord is responsible for maintaining the existing units and worksurfaces, and if they are in need of replacement, they must be replaced - even if that is before the programmed replacement date.
This is under the implied terms of your tenancey agreement, under the HHSRS and Environmental Protection law (based on hygiene).
You are also permitted to replace the kitchen units if you wanted to, and permission can not be withheld without a very good reason. You then will take responsibility for it.