I think this is the territory we are getting to with Joel now. His clean sheets record is very good, he calms the defence in front of him and makes me calm watching us. I remember in his second season, coming into a side that was completely all over the place defensively he kept something daft like 3 consecutive clean sheets. It was the only timer under Martinez we looked like we wouldn't conceede.
This is a lad who at youth level was ahead of De Gea. Now I doubt he will ever get to that level, and it it almost Kopite levels of delusion to suggest that he automatically will. However goalkeepers tend to peak at different moments and some do develop later, as they grow into their bodies somewhat.
For what is a youngish goalkeeper getting his first proper run his record of clean sheets and other stats are massively impressive. I believe he will continue to improve (and will need too) but people play down just how well he's been playing for us.
Our alternatives in the summer are to go and buy an elite goalkeeper. Could we entice away someone like a Lloris? I highly doubt it. Or we get a prospect. As indicated I like Butland, there are likes like Horn or Leno from Germany. However having seen Karuis and Feiler similarly highly rated from Germany struggle to adapt are they significantly better than Joel? Likewise Butland post injury, is he that much better than Joel?
I don't wax lyrical over goalkeepers. I am a tough judge. The only one I've seen for us better than Joel was Martyn (I only got the end of Southall).