Could (I'm not asking Should!) the Roman Empire have been saved? #SPQR Or even democratised?

The reforms by Emperor Diocletian and others were the start of the rot arguably at least

...

Perhaps with the provisio that: the second sons of all citizens should serve between 3-15 years in the legions or 4-20 years in the auxiliary legions , depending on family wealth, with Citizens able to volunteer for 18 years in return for tax exemptions and non citizens 20 years in return for citizenship.

Could (I'm not asking Should!) the Roman Empire have been saved? #SPQR made the Marian Reforms necessary in the first place

Could a mix of citizen-or Resident-conscription with serviceleadstorewards work?
Say allowing citizens to forgoe taxes in return for the old auxiliary 20-25 years of services? Or is it better to retain the "citizens can join the legions, non citizens can join the auxiliaries"?

Perhaps with the provisio that: the second sons of all citizens should serve between 3-15