Man have they been slow to make progress on that. I first started hearing about it early 2018 and here we are nearly two full years later and it still seems extremely raw. Maybe it will start moving faster now that Core 3.1 has shipped but the pace of progress doesn't give me confidence in Blazor.
https://visualstudiomagazine.com/articles/2019/09/26/blazor-...
https://github.com/SteveSandersonMS/WebWindow