Any way to make my aging Lenovo b575 become snappy again? If all else fails a new laptop suggestion would be nice

I have a Lenovo B575 with Arch and Gnome. Currently the CPU usage is jumping between 5% and 90% when having 4 firefox tabs open.
I already have a ssd installed so bootup is not an issue
Is there any suggestions on how to optimize it so that when I try to use a online pdf editor, the machine does not lag like crazy?
Are there any distros that favor performance and has a gui that looks great? I was thinking of reinstalling Arch because I loaded it with bloat.

If all else fails, are there any suggestions on laptops that are...
  • $500-750
  • have a touch screen > 13 inches
  • have a processor that can handle lots of chrome tabs open at once (at this point anything is an upgrade over my Lenovo b575)
  • one that can potentially run Linux (because screw windows 10)
  • I already have a decent desktop, so gaming is not necessary, I just need a laptop that can program and take notes with out stuttering
  • lighter than 5 pounds
  • My parrents are considering on chipping in on the costs, they would like a "respectable" brand like "HP" and would prefer retailers like Sams Club or amazon
  • Was thinking of this or this when it is on sale

What DE do you have installed? guessing that is the cause of it if you have something like gnome installed

gnome 3.22.2, any way to check which one? tried echo $XDG_CURRENT_DESKTOP, gave me gnome

what does system monitor tell you what is using up the cpu

Maybe you can buy a used chip that's more powerful to spice up your laptop, if the CPU is socketed and not soldered. Add some RAM maybe can help because if you're not using a dedicated GPU you can increase the VRAM pool for the iGPU and get better performance.
Other than those things I don't think you can do much else really.

Most likely you wont be getting a much faster computer, that model uses a old CPU which at the time was designed to "kind of" compete with the intel Atoms line at the time.
Sad thing is that the better the hardware gets the more bloated in general the software gets, even on linux, so even though it ran perfectly well 2 years ago, it may never live up to specs now a days.

memory upgrade, and a distro with LXDE / LXQT or XFCE desktop.