Slow browser responses on 5-year-old MacBook Air

I've got a MacBook Air 2020 ish 1.1 GHz Quad-Core Intel Core i5, 8gb memory. I don't really game on it the only game I play is Football Manager. I've noticed that it's becoming really slow not just while playing but all browser responses (I use Safari). I've backed it up on Time Machine and also backed up to iCloud. If I reset to factory settings would this help?

I'm open to suggestions, I can't really afford a new MacBook so if it's a case of my 5 year old Mac not being upto it I'll probably go back to a Window laptop.

Any help would be very much appreciated. TIA

[Re-Titled by Moderator]

Original Title: Slow responses