The rationale for investing in building such an aircraft is that you require it for your own armed forces and/or for export potential.
I would suggest that, based on recent history, and the competition from the USA/Russia/China and domestic programmes in nations such as Japan/Korea/Turkey, the export potential is low. (And BAe is in fact investing instead in partnering in the Turkish and Japanese programmes).
With the dramatic shrinkage in the RAF over recent years and the introduction of the F-35B the UK market for a Typhoon replacement is small, if a couple of squadrons are replaced by additional F-35A/Bs or UAVs such as Taranis perhaps no more than a couple of squadrons for QRA which could be filled off the shelf from the next generation US fighters for the USAF and USN now being funded.
In such circumstances I can see the lack of interest in the MOD/Treasury for investing a new European project within the next 20-30 years, especially with more urgent needs in other parts of the defence budget.
And, let’s face it, Bae is mainly a US company these days and there are more jobs in bidding for contracts to build parts for US aircraft such as the F-35 than a European Typhoon replacement.