MacOs Ventura problems, especially with Safari.

I don't know if I am the only person experiencing these but after I updated my M2 Macbook Air to Ventura, Everything turned terribly slow. OS is super heavy (Even though I am only web browsing and not running any special software). and the worst part of it is Safari...

It keeps lagging, worse than a Windows computer. Even it lags on opening a Google page. keeps reopening the closed tabs. and sometimes when I open something in a new tab, the whole page opens as a blank page. so if there will be no refresh and no website address on top.

Programs losing their default settings. for example: when I chose to open PDF files with Mac's default viewer, it turns into adobe acrobat later on AGAIN!