That's total crap. A huge increase in wait times is caused by companies unable to hire cheap EU staff, putting pressure on recruitment across the board. The Eastern European lorry drivers that propped up our haulage industry have gone home, meaning that hauliers are incentivising Brits to get LGV licences, putting pressure on other industries.
Cost of living crisis means that more civil servants are striking or working to rule to improve their pay, my dad waited months for his driving licence review because of that, not because of WFH.
Cost of living crisis, especially costs of childcare and the cost of the "shortcuts" (e.g. ready meals, ironing services) used to make working parents' lives bearable, means that it can be more cost-effective to be a single income family, removing (usually female) people from the workforce, again causing recruitment struggle.
Increased red tape after Brexit means that some of the staff that used to answer the phones are now filling export paperwork.
Staff can be monitored just as well at home as at work. Call centre staff are monitored by the same software on their PCs that they use to log the calls. The PC being at home doesn't affect that. Same goes for data entry staff.
People can’t ask their manager questions
I can ask my manager any question I like from my home office, and if his Teams status is busy then I can ask his boss or the whole of the rest of my team simultaneously. And the great thing is that I don't have people shouting questions across the open plan office any more when I'm on the phone to someone. I don't have people holding stand-up meetings next to my desk. In programming, systems administration, and other work that requires deep concentration, WFH is a godsend.