Absolutely not. They are trying to protect you, can you imagine how awful Safari would be if it let you sideload such nasty extensions? It would be just like Chrome, absolutely no market variation to speak of! Despicable.
It's really AdGuard's fault for failing to fit their functionality within the arbitrary constraints Apple decided was suitable for a runtime.
Chrome's decision is also entirely arbitrary, so it's not a great example. Firefox on mobile notable supports Chrome extensions, without any real issues or battery drain whatsoever.
That’s because there’s a limit on the number of filters per extension. uBO may eventually need to do the same.