[highland bagpipes]

I would agree that they're not suited to pub performance, but there are other types of Scottish pipes which are more suitable - the smallpipes, for example. The highland pipes constitute their own ecosystem, I think, which is separate from the session scene - that's to say, they're not really a 'folk' instrument like the fiddle or smallpipes. They're more of a courtly and martial instrument.

Bagpipes of any sort are rare in sessions with other instruments. The problem is the setup time. You can't just jump into the middle of a medley - even if you keep a set of bellows strapped on (not all bellows pipers do) you have too much pumping-up time to maintain continuity. And when you've finished a tune, players of other instruments also don't usually make allowances for the fixed set of pitches that Border or smallpipes have and will take off into a tune that needs notes you only have on a whistle or fiddle.