@Newdaysameday I'm struggling to understand your points.
As you say, tips top up the wages of the staff, but the question is why should they? In what other business is the customer expected to subsidise the employers' costs through the addition of a mandatory service charge?
There is a national shortage of serving staff - and of kitchen staff. Perhaps the reluctance of employers to pay decent wages is a factor. The national minimum wage is all well and good, but there is no enhanced minimum rate for evening and weekend working, or for Bank Holiday working.
There is no lack of understanding of how hard it is for a restaurant to make a profit. Like all businesses, restaurants have to deal with increased costs in the form of price rises for materials, staff, rent, utilities, finance and so on. Restaurants are not unique in this. What people are realising is that the quality of what is being offered - the food, the level of service - is being compromised by restaurants trying to reduce costs while charging more for a poorer product. Restaurants are alone in attempting to charge customers extra through increased "service charges" and "cover charges" and people are noticing and complaining.
And yes - I've seen the profit and loss accounts of restaurants and hotels, having run a restaurant and worked in hospitality for many years (including recently). UK restaurants have been put out of business by corporate companies cutting costs and holding down wages while being mortgaged (or leveraged) to the hilt. Now that interest rates have risen and consumer spending has collapsed, these chains are going bust as they were never really profitable in the first place. They existed to make enough money to pay the interest payments to their financial backers, not to make a profit per se, and once that becomes impossible they cut costs until the product becomes so poor that nobody will work for them and nobody will eat there.