I've noticed this problem (not the CPU so much as RAM and storage space) with my LG F3. Recent updates to Google services have bloated things enough that I have trouble applying app updates in its limited storage space, and multiple apps that used to work well together now no longer fit in available RAM. Sometimes I have to uninstall and reinstall an app to update it now. Things get cramped with less than 1.3 GB of internal storage, even with an SD card installed.
I'd love to see an up-spec F3 with double the RAM and gobs of storage (but keeping the SD slot and removable battery). I don't really need a hyper-expensive flagship phone, tempting as it may be. For all of the F3's faults, it has LTE, good RF performance in general, and outstanding battery life. It also puts the lie to the claim that you can't have a slim phone with a replaceable battery and an SD slot.