Spot on!
I love WFH 2.5 days a week - it saves me money on childcare/commuting costs, gives me more time with my family, allows me to cook more nutrious meals (I meal prep/batch cook during lunchbreaks) and ultimately I earn more because I didn't need to drop as many hours as I would have done if full-time in the office to be able to do balance work and family life. These benefits are good for health, wellbeing and the economy.
I also fully appreciate that WFH can be very damaging to productivity. I've experienced that first hand - being in a role with not a lot to do and no real impetus for management to up my workload because that also means they'd need to do more work. I am a manager myself now, and as you say the role of managing hybrid or fully remote workers requires specific skills and also specific data. It is such a delicate balancing act trying to address potential "shirking" when targets and performance metrics just don't give you the info you need to be able to say very clearly "you are doing less on the days you work from home and that is a problem".
I would fully support much more monitoring of remote working. Its a price I would pay happily to continue to benefit from the extra 7 hours a week I have at home (commuting/lunch break time).
I am concerned that companies are instead pushing for a return to office; its an easier way to address the problem people, at the expense of those of us who can WFH effectively. And I do believe it will disproportionately affect parents, carers and those with health conditions.
And before anyone pipes up that not all jobs can WFH so its a "perk" office workers should be grateful they had temporarily - I fully support all job roles in all sectors providing as much flexibility as is reasonable to enable people to have a fulfilling career and be economically active while maximising their opportunity to live a good and balanced life. The point is office work CAN be done at home, at least some of the time, so WFH is reasonable flexibility; if your job can't be done at home, it's not reasonable to WFH, but other flex may be avaliable.
As to OPs point - no, companies should not be paying for commutes. However, there may be a wider picture whereby companies have watered down other T&Cs and/or not offered inflation-matching payrises and/or offered new employment contracts on the basis of remote/hybrid working. Those companies need to remedy those issues and not just tell employees to suck it up.