That is a very effective use case, but until we live in hive cities, stadium-level device densities are an edge case. Developing a new generation to service the 0.01% of time phones spend inside stadiums seems inefficient.
They struggle a bit on Oxford Street which as stadium like densities much of the time. I changed networks to O2 as Three became pretty much unusable in that area. Three sell a lot of unlimited data packages which their hardware seems inadequate to serve.
If you have a season ticket to a Premier League team you're going to be in that density once a week or once a fortnight. Whatever the percentage of time that might be, that seems frequent enough to not be an edge case.
Lol. Season ticket holders are maybe 0.001% of phone users. Even if they are all whales, it isn't a sufficient market.