I agree, it make any sense anymore.
The way the original series developed the whole Regeneration concept was only really introduced with the Jon Pertwee version changing into Tom Baker. That was the first time the word "Regeneration" was used, and the first time it was established the Doctor and his people could do this independently and it was a failsafe that was triggered at the point of death - not for nothing did the first eight Doctor's regenerate either flat on their back taking their last breath, or at the point of death being propped up.
So as fantastic as it was as an idea it did have a logic. A science. The Tom Baker era established a Timelord could only Regenerate 12 times. And naturally as the series went on and was revived in 2005 the limitation would have to be addressed and dealt with if the Doctor was to live on. But while a 12 Regeneration limit might be too limiting for a series where the actor tends to do three years and leaves, I don't think it wise to just do away and leave no limits whatsoever, as Steven Moffatt appeared to do with the 50th Anniversary.
Still, Chris Chibnall has take it to a whole new level now by showing the Doctor isn't even a Gallifreyan! Indeed He isn't even a He! He is an 'It'!
So this formless shapeless super-being from beyond has replaced the Doctor we knew and brings a whole new mythos with it....
Who knows what the limits of its powers actually are.
The Dr might very be a sentient machine, an Ukltron or vision who mimiks whatever he is around and dealing with!
Would be funny if we were shown at the very end of time that the delaks had finally became intimate form of machine life, and end result was what we call the Dr!