You can improve the look by turning the grid off, it’s something that I’ve suggested a long time ago, they’ve implemented it, but it’s still not default 
It makes everything clearer to read and prettier, both in BP and Material graphs:
Edit -> Editor Preferences -> Use Grids In The Material And Blueprint Edtor -> tick this off.
… As for the rest, yes, the UI is pretty outdated in terms of design, but it’s functional and quite clear on what is where. While it would be nice to have a new fancy UI, personally I don’t feel that current design limits me when it comes to working in BPs. So I understand you, but I also see why it might not be a #1 priority for them.