This argument about LTNs is endlessly rehearsed in my local area too (Zone 2) and people come up with the same old saw about how it's led to bars, restaurants, shops etc closing down. It's horseshit. Places close down if they're not good or popular and/or if they can't make their rent and bills any more (which is a genuine issue, but a separate one). It simply isn't true for the majority of potential customers that they can and do only come to places if they can drive there.
The only people who think this is horseshit are idiots who think that everyone will walk or cycle everywhere because they want them to.
It really isn't horseshit. Where I live, I could drive to a set of local shops in 5 minutes where there is parking. Same for people who live near me. Loads of people would drive to the supermarket, do a big weekly shop (which if you have a car and shopping for a family you are never going to do on a bus) and then go to the other shops there have a breakfast/brunch in the really sweet little local brasserie.
Now it takes 45 mins to get to the same place because you have to go out on to very very congested main road and sit in idling traffic. So now I tend to order big shops online and I stopped going go to the other shops or the brasserie which is very inaccessible now. Guess what happened to the brasserie - which was always very busy and a brilliant business? The owner is best placed to say what happened to their business and I can tell you it was good and popular.
Of course this would be the case because the LTNs have totally siloed off little areas that make it hard to get to. Same for other shops, on my way back home I'd often stop at a bakery and a local off licence, now I can't even get to them without a huge out of the way detour to go there and come back round for what used to be literally a drive down a long road, a single turn and a drive down another. I'm not the only one in that situation. Loads of businesses had passing traffic like that where a quick stop on the way home was a source of good trade.
The delivery vans now have to do the journey I would do and will be sitting in idling traffic for ages. It's all a policy dreamt up by obsessive greens to no end (the time for cars on the road has increased because of congestion all on artery routes) and has really mangled the whole convenience of living in a big city.