There's nothing pointless about it. TloU and TloU2 are night and day in graphics, animations, gameplay. This gets them to bring the first game to the level of the 2nd while also getting more PS5 development in. Schrier himself believes that it is going to be bundled with the PS5 version of TloU2.
Development probably won't even be that much longer. Taking into account how quickly Lost Legacy came about, a TloU remake will be a lot easier for the team to work on. This is especially true when ND is still figuring out (or were) what their next game is going to be.
There are no downsides to this. TloU gets upgraded to the mechanic and visual quality of the 2nd game. It's not going to be super challenging work (especially after what we learnt about crunch on TLoU2). Gives the team more PS5 understanding before their new title, and it impacts very little else ND is or could be working on, because atm we only know that they are working on this and Factions 2 while their next game still gets figured out
And Bluepoint get to work on their next title, which means even more PS5 games sooner.
There is also a very good chance, they could stuff the story up and ruin the charm of the original.
There is alot of risks involved with this decision than you actually think. Graphics arent everything.