ʿāḇaḏ may well be translated as ‘tend/cultivate/serve/dress’, but it does not mean this. It means to ‘serve’, and the translations are trying to interpret this. Unfortunately not with the correct accuracy.
And this word is the same as used in verses 5 and 15, the two about ‘man’ and the ‘garden’.
Pre-fall, the ground (plants) and the beasts/creature were to ‘serve’ Adam. They ‘worked’, they were there for man, to sustain him, and to fill the earth.
God planted the garden. Who? Man? Then God put man into the garden to ‘keep’ it. ‘Keep’ - ‘šāmar’, to watch over, to have charge over.
Man tendered - watched over- the garden, but this involved zero toil or sweat. Genesis 2:5 should really be translated ‘there was no man for the earth to serve’!
But post fall, through what Adam did, the ground was now cursed. Now the ground needed toil and sweat, produced ‘thorns’, required ‘work’. Now man was ‘serving’ [working] the earth! Being dominated by its fallen (cursed) state. The plants were now ‘out of man’s dominion’. Plants and degeneration would lead to ‘weeds’ competing with the plants. The ‘tares’ have now been ‘planted’.
Essentially the fall (amongst other things.) went from God being the source for all of man’s needs, to man now having to be his own source - he was now not in the garden, he’d have to, as it were, ‘plant’ his own.
As for whether plants and animals ‘died’ pre-fall, this would be speculative. I personally think they did - because of the ‘cycle’ of replenishment, the plants/animals would be returning nutrients. And, it was the tree of Life that sustained man, and the animals had no ‘tree’ to attain this from. But, speculation, speculation that really doesn’t change things, doesn’t make a difference to what the Bible says elsewhere.... i.e. isn’t important to the overall ‘picture’.