There’s a couple of factors at play here which I think have conspired to convince him a new deal might be a smart move.
1 - Barcelona’s unwillingness to make a reasonable offer, despite years of him apparently being their ‘top target’ every summer. He has openly acknowledged the need for there to be a decent offer to facilitate his move, and must be frustrated that despite all their promises they keep prioritising elsewhere. He’d be forgiven for thinking this isn’t going to change any time soon.
2 - while he waits around for Barcelona to sort their shit out, he’s missing out on a significant salary uplift (almost double, if reports are to be believed). He must look at less vital players like Mahrez and Cancelo signing new deals and being paid more than he is, whilst he’s fully aware he’s one of our most important players - and should be paid accordingly!
If we’re willing to extend his deal for another couple of years with a clause that lets him leave in the summer of 2025 (his current contract length) for a release clause, then I really don’t see any reason why he wouldn’t sign a new deal.
Let’s face it - Barcelona aren’t going to sign him this summer, so he might as well get his salary doubled for the next couple of years - in which time they might be in a position to actually register him!