OP, you could let your child decide, just as you might do with a dance class or playdate.
I didn't feel my eldest particularly needed nursery and wasn't planning to send her, as she was happy enough without it. Sadly, as soon as all her toddler group friends started nursery, they became too tired or busy for playdates, plus their parents no longer prioritised playdates, probably realising that their kids had plenty of social opportunities at nursery. So mine was suddenly lonely and wanted to go to nursery at three. I thought she would like it as she was a super sociable child.
Parents were asked to volunteer at the nursery to cut up the fruit, sweep up etc so the staff had more time to spend with the kids. That worked great and gave me a good chance to see what went on. I gave her the choice about nursery, asking her every day whether she wanted to go. Much to my surprise, over the course of three weeks she went less and less and eventually stopped altogether, so we gave the place up. She was a very chatty child, but it was only over the coming months and years that she was able to explain why. Here are some of her reasons:
It was supposedly a free-flow nursery where the kids could choose what and when to play. But the kids were guided in certain directions at certain times, and the outdoor play often didn't happen at all because it wasn't convenient for staff. Too muddy, too rainy, too cold.
Too many kids. She couldn't get stuck in to playing with another child for long because all the distractions would pull them away. Likewise the staff didn't have time for long chats. She preferred to play with one or two or three kids at a time rather than be in such a hectic environment.
With several dozen kids, invariably at any given moment at least one of them would be upset about something. My dd wanted to fix it for them and it bothered her when she couldn't. So she was always slightly distressed, even though she wasn't the one who was missing mum or squabbling over the toy or sad that the blue crayon was missing.
Carpet time. I guess this was meant to train them to sit still so they would be ready for school. But some of the kids couldn't manage it and were constantly 'failing'. My dd actually said, 'Carpet time is when the teachers make us sit down so they can tell the boys off.' It felt that way to me too! Even though she wasn't being told off, she found it unpleasant to listen to the kids being chivvied to sit still.
Because she couldn't explain all this at the time, the best way for me to know whether nursery was benefiting her in the way I'd hoped was to let her choose whether to go. In the end she decided it wasn't worth it, and we worked harder at finding friends for her elsewhere.