... would you want to be a bonsai? I mean, obviously plants are merely compositions of cells without any nervous system or other means of processing higher level information that would allow them to make conscious decisions or experience the world in any way close to how humans do. This question is not a thought experiment, it's a metaphor.
So, would you? Some people think that turning a tree into a bonsai is literally torture. After all, they are confining you to a much smaller form factor than you would naturally grow to, leaving you just enough resources to stay alive. On the other hand, they are taking care that you get the right amounts of these resources regularly, an amount of care that no other kind of tree would ever receive. And they're not doing it out of necessity, they're doing it out of love. I can't imagine there being a way to keep a bonsai tree alive without love. There's no reason to have a bonsai tree other than wanting to have a bonsai tree.
Is it worth the complete loss of freedom to be at the receiving end of all that love? Is it worth having your body shaped in an unnatural way as decided by a higher being, to receive a commodity that only those higher beings are able to give in amounts that no other member of your species would ever know? Being completely at another's mercy for the incredible opportunity to live your life in a world where you don't belong? A loving relationship across the steepest gradient of cognitive abilities conceivable?
We humans are so focused on our autonomy that imagining the complete loss of it automatically feels dystopian to us. But what if love enters the equation? If giving up everything granted you an amount of love that that was otherwise impossible to achieve, what would you even use that autonomy of yours for? Being a bonsai pot sure is a quick way to end up as compost, but so does every other plant eventually. And whatever you do, it's not like your life is going to be any more meaningful one way or the other, as every life is ultimately meaningless.
But then there is the appeal of growing into an old, mighty, tree. Maybe even one that bears fruit. Some trees are hundreds of years old. You could provide shade, you could shelter whole populations of animals and you could feed families with your fruit. You could weather storms, have branches being torn off just to regrow them. You could have a young couple engrave their initials in your bark, only to outlive both of them and carry their mark into the future where their grandchildren are playing on a swing attached to one of your branches.
You could be all that, or you could be a bonsai. There's no right or wrong decision. The choice is yours.