Updating an Mid-2007 20" iMac stuck at OS 10.9.5

Some years ago Den.thed provide this advice to the question on possible updating a 2007 20" iMac.

"It is to old to waste any time or money on to update the hardware. Plus it can only run up to 10.11 El Capitan, which Apple no longer provides security updates for.

Sadly, your best bet is to retire/recycle it and look into getting a new or at least a newer model Mac."

Since he mentioned El Capitan, just wondering how to get it to 10.11 or even 10.10 since updates don't seem to go beyond my current 10.9.5?

The iMac is still useful for routine functions, has an updated HD and RM from years ago. If there's some way to get it 10.10 or 10.11 it could be use it for streaming w/ my Spectrum cable provider. Current they don't seem to support OS 10.9.5.