I've already answered this at least twice.
Very few companies in the world have the sort of liquidity that they can find a billion quid or even a fraction of that down the back of the couch. When Elon Musk bought Twitter, do you think it was all his own money? Of course it wasn't. He fronted a portion himself and the bulk of it he raised from equity funds and banks who saw him and his vision as an investment.
Same with ENIC. They fronted a huge amount of money (iirc circa £230m) on the stadium, then turned to equity funds and banks for the bulk of it.
There is nothing stopping any club or owner doing the same.
Forest could tomorrow put together a proposal to build a new stadium. Their owners do not have enough liquid capital to pay for it up front, so they would also have to approach investors and banks or local authorities for the bulk of the balance. Those investors would then consider the relative risks of loaning a small fortune to a club teetering on the brink of relegation and with a pretty small commercial reach. I'm sure Forest would get the money, but the repayment term would be extremely short and with very high interest so as to protect the risk for the investors. And there is no way Forest could ever be successful enough quickly enough to ever reach those terms. This is exactly what happened to Leicester and exactly what will happen to Everton if they get relegated. Them building a new stadium from a position of extreme weakness is an enormous risk and there is a very strong chance that they will go the same way as Bolton and Sunderland after their construction of new grounds.
There is always a risk. North London could be hit by an asteroid next week and that's the end of that. But ultimately it is up to the investors to assess that risk and reach a conclusion.
This conclusion is the only thing FFP takes into account. So in Tottenham's case, investors looked at a state of the art, multi purpose venue in the capital city that was also the home of a PL ever-present who qualify for Europe most years, and they came to a very generous conclusion:
We will spread repayment across 23 years at appx £30m per year.
From this point on, Spurs are duty bound to add £30m to their annual expenditure sheet. That's the only number FFP cares about.
Is there a chance Spurs at some point in the next 18 years will default on that repayment? Of course there is. But it is infinitesimally small and therefore the various investors didn't pay it much attention.
This is how every investment, indeed the entirety of capitalism, works.
The reason I brought Arsenal into the discussion was to compare risk levels. Despite at the time (and still) being a bigger global brand than Spurs with a larger total fan base and undoubtedly more prominent success (they'd literally just won the PL with the famous Invincibles team), their stadium finances were still considered more risky by investors, since repayments were tied solely to sponsorship, which relies solely on continued success on the pitch.
Had the Emirates also been a state of the art multi purpose venue, which it absolutely isn't, Arsenal would've also secured much more favourable terms and wouldn't have entered the era when selling Henry, Cole, Toure, Van Persie and Fabregas became a necessity because sponsorship wasn't increasing as had been forecast.
