Mojave Time Machine

This concerns a relatively new but still long-standing problem with Time Machine; it does not do what they say/said it would do in terms of deleting old back-ups to make space.

Once again yesterday, notification popped up that Time Machine backup had failed. So I did what lately I have had to do, open the backups folder and move a bunch of them to the Trash. The process of emptying that trash bin then takes a ridiculous length of time when (as I understand it) all that is really required is marking those sectors as empty on the Time Machine drive.

For the past few years, claim to the contrary, Time Machine does not delete old backups as the drive begins to get full.

The only "fix" that I have ever seen is either to re-format the drive or add another drive. (Have you noticed that ever since Steve Jobs died, Apple "stuff" has been showing some significant lapses, inefficiencies and unacknowledged problems. I began using Macs (after Apple ][s) in late 1984.)

So what I've been doing is opening the back-ups folder, selecting a brace of folders and moving or sending them to the Trash.

Given the amount of data and whatever the Empty Trash command means for these kinds of files, it can take literally 12–24 hours for the files to actually be "deleted."

I can not simply leave them in the trash because if I need to delete something else, the command will begin the hours-long process of deleting, apparently one byte at a time.

I thought I had successfully used a Terminal command to Force Empty the Trash, but (1) the procedure I used last time produces an error (override rw-r--r--  root/wheel restricted for /Volumes/My Passport 4TB Time Machine/.Trashes/502/2021-12-11-003404/Macintosh HD/).

Because of that string of failures to immediately empty the Trash, I searched specifically for Mojave, since that is as high as I can go (I am using a 2012 Mac Pro (desktop) and am not going to buy a more recent one until Apple markets a model with Apple Silicon CPU).

I found variable instructions, and tried them all. None of which accomplished the goal.

What I really would like is a way to have Time Machine actually perform its making-room function as advertised. Failing that, does anyone have a way to make the Trash simply delete the backup folders that I have put in it instead of having to take several hours to do so?

And, as long as I'm on the topic, does anyone know how to make Time Machine actually automatically delete old files to make room? I have dedicated a 4TB drive to it but also have nearly 40 years of files, so the back-up folders have a LOT in them.