We thought about it but I’ve heard a lot of leaks happen due to tiled shower areas. While it looks marginally better we would rather remove potential future issues. Same with the tile trim on the recess, it’s possible without (and looks a bit nicer) but that’s a weak point for water ingress.
Looks very tidy. Also a decent sized room. Having a Niche is essential imo. Were you not tempted for a tiled on shower tray?