>>149334605As the Swiss anon (
>>149334817) said, plus there still are existing structures of the old stadium from the 50s underneath - that one had to be rebuilt because it had a running track (which turned undesirable) and for safety reasons. That's also a bit of a nuisance these days. Parts of the structure are relatively old and not very modern, and the new ones were somewhat built with 90s who cares mentality.
The stadium was renovated for the 2024 Euros, it worked well. But it needed that renovation in order to be allowed to host, and in 10 years or so, maintaining it will begin to cost so much that it slowly becomes unsustainable. It won't collapse, but in 20 years, it will be a highly unprofitable stadium with structural issues. I suppose it becoming a safety hazard is another 5 years from that
The stadium is also too small in general
That's why the new stadium has to be built within 20 years. Beyond that, the club will take significant financial losses and also miss out on future events
If you really really really wanted to, you could probably play there for another 30 years or maybe a bit more