Well, then don’t. Just ride, do some hard/max efforts every now and then.
Really, if you just get a service you like (Rouvy, Zwift, BigRingVR, whatever) and put your trainer at use, riding these virtual routes, it’s just like riding outdoors.
You seem to have experience enough, so you know what feels/is right and you will skip a day if you don’t feel up to it.
A plan just may force you to do whatever is the prescribed workout for that day.