S, Happy New Year (in English this time LOL)
There will be others who are far more au fait with the limitations of the tip-jet system, but I believe it was noisy, not terribly efficient (ie high fuel consumption) and there were problems sealing the air/gas in it's passage through the M/R hub to the blades.
Of course, that may have been in some part due to the limitations of technology and materials for such seals some 60 years ago.
But I'd be interested from an academic point of view if anyone could throw some light on the question - VFR