Does it make sense to upgrade the laptop RAM?

Hello guys i have a laptop ideapas s145 14 inch

Windows 10 Home 64bit

CPU: Celeron 4205U 1.80Ghz

RAM: 4GB DRR4 2666Mhz

128GB SSD

I use the laptop for text editing, surfing, emailing

You can upgrade the laptop up to 20 gigabytes if I upgrade the laptop to 8 gigabytes of RAM I notice that the difference in performance when idle is about 46% of the ram occupied when I open a few pages and open office when the ram is 75-90% full

You will not notice a difference. Since you only have 90% RAM utilization even under load.

Probably. Hardly bring anything.