Heavily disagree with the business case here. It's not as simple as rises = more revenue.
There's 3 major points in play.
1. Maybe an extra few percentage points will not affect the attendances of "ageing fans" who are most likely financially settled later in life. It does however effect the attendances of younger fans, who are the next generation of fans and it prices them out of the market during a cost of living crisis. That is trading the future of the club for the present and is irresponsible in terms of long term growth. There's hundreds of famous companies who have fallen into the "revenue at all costs" trap and ended up selling themselves out of existence, Time Warner/AOL probably most famously.
2. The reason that every advertiser, marketeer and media creator wishes to attract the 18-35 demographic is because brand loyalty created at this age of lasts a lifetime, and ensures that as their finances grow then you can take advantage of this in terms of commercial revenue. Sponsors are interested in creating that loyalty and positive image because an 18 year old might not be flying on Etihad flights now, but there's a good chance that they will in several years time as they've moved onwards financially. It's the reason why banks fall over themselves to give accounts to students.
3. One of the major attractions of a live football match is being part of an atmosphere and making the stadium a "destination". Ageing fans tend not to be the people who create the raucous atmosphere, that's the people that we're pricing out. The club wish to have this great atmosphere that they can help market themselves globally based upon, look at their socials for a few days after a good atmosphere, they cannot stop showing clips. Because it generates a buzz, an excitement, an attraction for people to "live their dream" and visit the Etihad and be part of that. Having a crowd of 40+ year olds sat on their hands is not appealing to the TikTok generation who we are competing against with Bayern, Real, Barca, Liverpool, United, etc for future revenue
It's a short sighted, bad faith and ultimately self defeating move that is going to sour relationships between the club and its most important fans. There's a reason all channels added fake crowd noise during Covid, that noise has a financial value.