I have no source for this guess of mine yet I would think that Padel attracts a younger , faster, fitter crowd so the demographics is skewed towards the 10-40 age range ( just to put a limit on the range ) with the 40-70+ demo being somewhat fewer and far between. Like a rather steep drop off after a certain age.
Both would have viewers ( on youtube or whereever else ) that would be attracted to watching the elite athletes compete against each other.
it does seem like something that would work like this: the European players who are into Padel in their early years would tend to gravitate towards a more moderate game such as pickleball that seems perfect for the elder athlete- in their 50-60-70's.
this is what happens to squash players for pickleball. at least it is my experience and from hearing about it.
tennis players move to pickleball .. squash players move to pickleball.
and I can see that Padel players as their age-out of competitive Padel , slowly move over to pickleball as the skills are translatable and they can use their tactical game to their advantage in the seemingly 'slower' game of pickleball.
Does anyone have a source for hte demographics of each , say in the USA for pickleball and for Padel in the UK or Spain , as an example.