Alternatives to CleanMyMac for RAM Swap & disk cleaning?

The absolute worst "feature" you could bring back is RAM swapping. The OS already does that itself as necessary. There's no possible way a third party vendor would know better than Apple what the most efficient way to do that is.

All security you could possibly need is built into the OS. Third party apps add nothing. There are no viruses that can affect macOS. Trojans go right past AV software since they can't know what it is you're installing and/or running until after the fact. The entire System folder is cryptographically sealed. There is no malware of any kind that can alter one bit of it.

Is it possible to make a mess of your computer? Sure, by installing Trojans that place themselves in your user account. But that also makes them relatively easy to remove.

Other than that, there is no protection of any kind for believing scam emails, messages or popups that claim you have 38 viruses and to call some scammer's phone number. Or, an email or message that claims they have naughty video of you (or more recently, claim to have installed Pegasus on your device). But don't worry! For the sum of some randomly chosen amount of Bitcoin money they tell you to send, they'll make it all go away.

The only protection against such social engineering is yourself.

Before going any further, it is worth noting that merely uninstalling non-Apple "cleaning" scams is insufficient to reverse or undo the effects of having used them. It has been my experience that nothing short of completely erasing the affected Mac is required.

Now, please start from the beginning and describe the problem you are experiencing. RAM Swap is not sufficient explanation since memory contents of memory are routinely and constantly being swapped in and out of mass storage, and Mac disks do not require and cannot benefit from "cleaning".

Be prepared to erase the Mac though, since "cleaning" apps are destructive in nature. It's what they do. They are scams.

is there anything else I can do to "optimize" my MacBook and help compensate for the RAM limitations?

Yes, sell your Mac and get one with at least 16 GB of RAM. Whether you're talking about a Mac, Windows or Linux machine, 8 GB is bare bones these days. Basically only good enough for surfing the web and reading emails.

Plenty of people are running Big Sur in 8 GB RAM. It is not an abundant amount, but it is more than sufficient.

Gave me the impression that there is continuous buildup of junk from just using the internet.

Of course it did. That's how those scams work.

It stands to reason all my Macs have accumulated the same buildup of junk. They work fine.

I reiterate your problems are almost certainly 100% attributable to using "CleanMyMac". Erase the Mac. Reconfigure it. Upgrade macOS if you wish. It will work fine.

Until you mentioned the Adobe CC apps, I would have readily agreed with John Galt. Erase the Mac and set it up fresh to make sure any added junk is gone, and it would likely be just fine.

But once you add apps like Illustrator, Acrobat Pro and such, then you're very much stretching what 8 GB of RAM can handle.

I agree. Adobe CC changes things.