While a page file is definitively slower than RAM, it's not a given that simply using one will make the whole system slower. As long as the kernel only sends rarely used pages to the file, the slowdown in writing/reading them can be made up by having more RAM available for the filesystem cache.

I don't know if this was improved in W8 or W10, but in W7 and before the paging algorithm in the NT kernel was definitely subpar, having a pagefile always reduced performance, because applications in the background would be swapped out even if plenty of RAM was available, so going back to an application meant that it was unresponsive until the kernel swapped it back in.

Windows 7 actually pages once you use HALF of your RAM. That's crazy. It's starting to page after I use only 8 GB! 8 GB is free and it's paging!

I ran windows xp without a pagefile for a while, no major issues, programs crashed if they ran out of ram.

Windows 10 has ram compression, but as I have an ssd now, I turned my pagefile back on

When I used windows, I would have a partition just for the page file, at a fixed size to avoid fragmentation.

No idea if this helped.