The Emilia-Romagna race track based in Imola, Italy looks like it has had it's last Formula One race today. The track previously held Formula One Races between 1981 and 2006 under the name of the San Marino Grand Prix even though the track is in Italy. The problem is Italy already has another race using the Monza track and F1 cannot justify 2 races in the same country.
The racing calendar maybe up to 24 races per season, but as a sport you have to follow where the money and growth is. Hosting a Formula One race is not cheap and there are plenty of host venues prepared to pay for this privilege. As an example next week the race calendar moves to Monaco who pay $20 million to host the race each year until 2031. The Zandvoort track in Holland pays $32 million for these rights and expires in 2026. Contract costs vary depending on contract period, popularity and the location. Monaco being the original street circuit race on the F1 calendar is on borrowed time as this is not a racing spectacle type track.
When you consider Bahrain, Saudi Arabia and Qatar pay $55 million hosting fees per year which pays for hosting rights and team travel expenses and why the likes of Monaco are being squeezed out. The Great Britain race held at Silverstone comes in at around $25 million so less than half what others are paying. This is a business with the costs rising as demand grows which will ultimately end up seeing who is prepared to pay higher hosting fees.
If we look at the current host countries Australia, China, Japan, Bahrain, Saudi Arabia, USA (Miami, Dallas, Las Vegas), Italy, Monaco, Spain, Canada, Austria, Great Britain, Belgium, Hungary, Netherlands, Azerbaijan, Singapore, Mexica, Brazil, Qatar, Abu Dhabi. The one race per country rule has been ignored for the US due to the idea of growing the fan base. They expect to add a street circuit in New York within the coming years along with a London street circuit.
There are not enough racing weeks in the Formula One season to satisfy the demand for host races. When we consider Germany, France and Portugal have fallen off the schedule due to finances with host tracks not being able to raise the funds required. Russia was removed due to politics and sanctions so there is many countries who used to host a race each year not even being considered now.
Vietnam has a new street circuit/track already built a few years ago and are expected to be added to the calendar, South Africa with their Kyalami circuit could also be an option, but funding would be a problem.
F1 funded both Las Vegas Grand Prix's thus far with a race contract until 2032 which included a permanent racing paddock costing $500 million. F1 is investing in areas where they see the growth and why the older permanent tracks are struggling to compete with the new thinking temporary street circuits.
There are 52 weeks in a year and if you consider the off season and testing account for 15 weeks. There is a mid season break of 2 weeks and then travel time between races the maximum races would be somewhere between 28 and 30 per calendar season. 10 weeks of 3 triple headers if you had France, Germany and Portugal reinstated would then be possible. I do think the racing calendar will settle at around 26 or 27 races per season and add sprint races on a Saturday to maximise the racing being offered to fans.