...remasters? Conversion of tape to plastic to mp.... Newer, better(?), tech available for engineers. Zappa [iirc] made his plastic lp's 22 minutes a side as that gave the optimum wiggle room for needles, both at the presses and domestically. Led Zep (ahem) re-released an awful lot of original material.

and anybody who cares about that (or just wants to support the artist) will buy the new version.

That's not what I'd define as constantly. And I have no problem with an artist wanting to release their own music this way, but if it were the industry norm I imagine I'd find it insufferable.