I think I've posted how I use yogurt and cottage cheese containers as pots for my starts. I have some that will be going on their 3rd or 4th year.

I remember your system. I'm glad you reposted it. It's a great way to recycle/repurpose those containers.
I have a couple of questions on your inverted yogurt container system. Do you bottom water your plants and let the water soak up into the soil? How long do you grow the plants in those containers before you transplant? I am wondering about how long you can grow a start in those containers before the roots spiral around the wall and the plant gets root bound?
FWIW, I have mentioned that I started using
slotted net pots for my starts...
The advantage to those net pots is that it is supposed air prune the roots and prevent the plant from getting root bound. It does a good job on that aspect. Also, I have not overwatered any of my starts since I switched to using the net pots. The slits in the sides keep the soil moist but not waterlogged like I did with other non-net pots and then had to toss out a lot of plants due to mold issues. My fault, most probably, but I have never gotten any mold in the net cups.
I bought the heavy-duty net cups, and they have 2 years use so far with none breaking. I just wash them out after I transplant them in the garden. At less than 20 cents per net cup, it's a pretty inexpensive investment for something that should last many years.
Of course, repurposing yogurt or cottage cheese containers is even a better deal plus you keep some plastics out of the landfill for a number of years.
Frugal Tip: Don't buy cheap potting soil!
The first year I used the net pots I bought some nice Miracle-Gro potting mix with fertilizer. My starts were fantastic. All of them were tall and strong. I made the mistake thinking it was mostly due to having switched over to the net pots. Last year, I bought some no name bargain potting soil on sale thinking I would save money.
Turns out the seeds sprouted fine, but they just never took off nor grew well on my potting stand. After about 5 weeks, I had to start all over again with a quality potting soil. It was really a waste of time, labor, and money using that no name low quality potting soil. Of course, I did not know it was not very good when I bought it. But this year I am going back to the Miracle-Gro stuff.
I also plan on trying some of your inverted yogurt containers method this year, which is why I asked a few questions earlier. I am open to all possibilities. Most of my starter failures in the past were due to overwatering and subsequent mold problems. But I have had more luck with bottom watering with the net pots, for example.
I have been mainly starting tomato and pepper plants about 8 weeks before transplanting. This year I would like to try the net pots and the yogurt containers side by side to see if either system works better for me.