I suspect they are trying to reduce their headcount without paying redundancy, by getting employees to leave.
WFH or hybrid opens up work for people with childcare responsbilities - due to shorter childcare hours without having to commute, people with disabilities or health issues, people who don't live near cities with more expensive housing where all the jobs are. I've had jobs that aren't possible for WFH like retail and childcare before, it doesn't make me think that no one should WFH because some roles can't. Every role is different.
I'm hybrid, I like coming in sometimes, I'm able to work more hours as I don't have the commute and I have health issues and it makes it easier, I'm doing an extra day a week since Covid. I work longer days on my WFH days and I still have more time as I don't have the 2 hours commuting time. Also, my OH is hybrid and he shares the family/house responsiblities - WFH isn't worse for me as it isn't all left to me.
I can focus more at home as there is less noise and distraction so I get more work done.
About spending more in the office, I don't as now they have upped our office days by a day a week, I'm spending more on commuting again. I don't buy any food or coffees out on office days like I did before and bring in lunch/instant coffee. Less money on commuting has helped fill the gap left by inflation, stagnating wages and the CoL.
I'm also in a junior position, although I have many years work experience and I'm not finding it a disadvantage. I work very closely with my team who are based in other offices around the UK and we still have good working relationships. It's not the same as being in an office together, but since we are all in different locations, we are never in the office together anyway!
edited due to spelling