Many people want the experience of wait staff at the table taking an order, but also don't want to pay for it.
Everything has increased in price that's involved in having a meal out, the food, the fuel, the cost of the people cooking and delivering it to the table, but although people know this because they are living it, there's some sort of disconnect where it applying to restaurants, pubs or hotels are concerned.
Then add that there's a shortage of people available to work in hospitality and so those jobs are needing to increase wages to attract and keep people and your 'experience' costs money - is it something you're willing to pay for? Or are you going to complain about higher prices? More staff means higher prices.
Personally from the other side apps have pro's and cons, one of the big pro's though is that people get what they order, they've made the order themselves, and there's less margin for errors. Though there's also less margin for blaming someone else when you've cocked up your own order because you did it yourself - some people don't like that bit though. Half the 'experience' is being able to talk down to and attempt to humiliate the service staff for some.
There's less people walking out without paying as well, and less people challenging the bill for non existent reasons just to try and get it cheaper.
The cons are no control over how the orders come in, you can get 20 orders hit you at the same time, where good waiting staff will space the orders to allow a flow of orders and quicker service rather than one big hit. And if you have a large table ordering individually then there can be a load of orders accepted between that tables first and last order meaning some people at the same table have their meals and others are waiting because other orders came through in between.
And as it's been ordered on an app, service is expected faster ime - but no matter how your order is taken, the food still takes the same amount of time to make and goes in a queue.
Where I work we don't use one, but I have in the past, we get asked fairly regularly why we don't have one, about the same frequency as being told people like the fact we don't have one. So from my experience and this thread and others where people say that they do like them, it would seem it's a fairly even split between those who like and those who don't.
The ideal would be businesses using both, but then paying for both staff and an app might not be feasible for all businesses.