Portability is overrated for sure.
But next-to-me types do have a lot of advantages. Especially when mums have just come back from hospital, they're not necessarily going to want to get out of bed and walk to get the baby. Being able to put them into the cot without getting out of bed is a massive benefit.
And that continues as they get older, when they wake up multiple times per night.
They do grow out of them quite quickly, and at that point you can get a proper cot. There are a couple of options there again. Firstly, it's much easier with 0-4 cots to get the wooden bit second hand, and buy a new mattress and sheets, which is one option. The other aspect is buying something like the
Ikea Gulliver, which once they're about 2-3 you can take one side off and it works for a few more years as a bed.
FWIW, we bought a second hand next2me as well and then just bought a new mattress.