If newer kernels continue to support all architectures, they would just get bigger and bigger over time. Old hardware is disappearing from being used and the code supporting them is loosing relevance. So, IMHO it’s a good compromise to keep the old still supported kernels for older hardware and to focus on adding support for newer hardware in the newer kernels, otherwise the kernels will become really huge in size which would be a disadvantage for the majority of users.
So, @sktelios I hope your issues are not directly linked to the kernel, in this case you would need to create a custom kernel.