Altera were roadblocked by relying on Intel nodes. Their new product lines (Agilex 9/7/5/3) are excellent however, despite being 3 or 4 years too late to the market. I've been lucky enough to have early access to them. It's going to be an uphill battle for Altera to win back lost business but based on current performance, and looking at AMDs roadmaps, I wouldn't put it past Altera to take the lead again.
Being an independent company is almost certainly going to give them an edge going against Xilinx under AMD - atleast when it comes to the pure FPGA play, and there's been surprisingly little innovation in that area (although I never found out if they actually got hyperflex to work)
It's worth investing some time in it now. The tools are a bit more fleshed out along with the documentation, so it's not the pain it once was. It's been a godsend for some image processing work I've been doing of late. The performance improvements have been phenomenal.
