The M1 is a CPUM1 vs Ryzen 5800U is not valid comparison since M1 is not CPU. In other words, it has no support for external memory.
The memory sits on the same package... So it is external, not that it defines what a CPU is.
By definition a CPU is a CPU by having a integer unit and a floating point unit. Which is M1 has....
The FX Chips are considered quad core even though they have 8 integer units is because they only have 4 floating point units. Each module of two integer units share a single floating point unit.