But what do you think when watching him? Is he "average at best"?
You can't really answer this question when watching football, unless we're talking about some extreme situations / players.
The problem with human is you'll always be comparing current De Gea to the players you saw currently / you remembered. And current De Gea is probably
close to his top level. It really doesn't get much better than now, but if you want to compare average over the course of the season, this is where stats prove useful.
So for shot stopping he is somewhere in the middle, although recently he's been great. And that is reflected in the same stats/parameters.
If Raya has been doing very well on some stats then over the course of the season he has been
at least on Dave level. It might be different to what De Gea is now but that is not the point, the form/luck will fluctuate.
I always suggest to use xG parameters to group players in 3 buckets:
Significantly below average - poor players or bad luck (we can't talk about bad luck after 20 games played, but this will play a role for GKs who played less games)
Average - they are OK, sometimes good same times worse but it's difficult to prove their super ability against those stats
Above average - players very good at this particular aspect or very lucky (we can talk about shotstopping, but also converting chances - and Haaland & Rashford are way above average in this).
Over the course of last 5 seasons, De Gea was twice in the above average group (17/18 he was killing it, last season he was top 3), and 3 seasons when he was average. This season he basically needs to continue current form to end in above average group, what I think is unlikely but possible.
All in all its just difficult to prove De Gea is amazing shot stopper. At the same time it is very easy to prove he is below average in almost every other aspect of goalkeeping. I also can't imagine anyone is watching him play and thinking he is good enough on the ball. Sweeping I think is more of tactics used by ETH, and claiming crosses is bottom of the pack.
There are a few goalkeepers who are above average in all key areas, I don't know if they are ready to step up but it's not like there are no options to choose from.
We aren't getting Alison who is comfortably the best gk in the league, but that should not stop us in going after the GK that can be that level in a year or two. De Gea isn't that guy (also because of age).
The problem is - we need a goalkeeper who is arguably better than ALL P.L keepers if we are to replace DDG. Not someone who is better than most. Raya isn't a bad keeper, but is he top-3 in the P.L ? Not in my opinion. So why should we even have a debate about DDG and Raya ? I can imagine 2-3 goalkeepers in the world who MIGHT be available and who is at the same level or maybe marginally better than DDG - Raya isn't one of them
I'd say in EPL alone you can probably name 2-3 goalkeepers who are available (not playing for big clubs) and significantly better than De Gea. And Raya is most certainly in that group.
It's not a question if there are better GKs available than De Gea, but if they are good enough for us long term. Only the summer will give us answer (assuming we will trust Ten Hag on the decision).
Raya might not be the answer but it's a quite safe bet.