I have flown a number of aircraft with TCAS fitted, it is without doubt a great SA builder. Tornado spent a fairly large part of its time floating around VFR at LL where TCAS was a help (though it had limitations at LL and wont stop you hitting a glider or microlight), we also didn't have a radar that could reliably see other aircraft . Typhoon is a different beast all together, most sorties consist of transiting under an ATC service to an area of segregated airspace where you then conduct high energy manoeuvres (TCAS doesn't work when manoeuvring hard in close proximity to other aircraft and has to be turned off in these situations). Don't get me wrong I would love to have TCAS in Typhoon, especially for OPS when ATC is often somewhat looser, but it is just another sensor, Typhoon has numerous other sensors which can build SA, in addition to the measures that have been mentioned above: planning, deconfliction, CADS, an ATC service, not to forget the rev backup of looking out the window and doing a proper scan! The bottom line is that there is a reason most FJs around the world don't have TCAS fitted, part of it is cost of course but also it is seen as redundant in many of the scenarios where we operate. Maybe that will change as we all get more litigious and safety focused and that will be fine, just be clear it is not a panacea for avoiding MAC, especially in a high performance FJ.