I was going to start a thread about this very topic!
I formula fed my first after a rough start. I'm now exclusively breastfeeding my second, who is 4 months old.
I've had some real issues and was able to see a lactation consultant just before lockdown, which I think encouraged me to keep going. Had I not seen her and received some fantastic support (at a time when the health visitor said I needed to top up with formula), I would have given up.
I have a bit of a love/hate relationship with bf. I'm keeping up with it because as you say, there are no visitors so I don't feel worried about people commenting on how often baby feeds, I don't need to feel self conscious, I'm not trying to plan car journeys or days out around where I can feed...etc. The health visitor isn't weighing babies any longer (and my baby dropped centile lines at the last weigh in, so she should have been weighed really!), so I no longer have a weight to obsess over. I just go by how baby looks, and she looks fine.
I was also thinking that if we got coronavirus in our household, that at least baby would get some antibodies through breast milk. I was also worried about not being able to get hold of formula, but I think that's probably not an issue now.
I think I would prefer to give up (i want my body back, to not be feeding all the time, to wear a nice underwired bra, to be able to wear a dress without silly flaps, to not need bra pads, to not be leaking all the freaking time, to have a bit more time to play with my eldest, to be able to have a lie in or evening/night off, to have an early night, to know that baby is definitely not hungry because I know how much milk she's had...honestly there are so many reasons!). Were it not for covid, I would probably be back on the formula by now. It's mostly fear of not being able to buy formula, and the antibody thing, which is keeping me going.