Is it worth upgrading to SSD on Late 2015 iMac 21.5 with 8gb ram for OCLP

I have a late 2015 iMac 21.5 with 8gb ram that has always been super slow and annoying.

I am considering buying an external SSD for booting (which should improve the speed a bit), and then upgrading the iMac with OCLP to Ventura or Sonoma.

The problem with the 21.5 iMac is that I can't upgrade the Ram, so I would be stuck with 8gb.

With that being said, is it worth it to go through the trouble of buying and setting up bootable SSD and then doing the OCLP process, or will be still be too slow with 8gb ram?

Thanks