I know I'll get blasted for this, but:
In America, the Blue Angels and Thunderbirds demonstrate maneuvers which can easily go wrong, hence relatively high levels of danger. There are no inherent military benefits to their displays; they rank next to letting movie stars and congressmen do emergency surface procedures in submarines (and possibly sink Japanese ships). Pure
PR activity, outside the proper remit of the military; as a taxpayer, I object to providing 'toys-for-boys', when I actually paid for military airpower.
Airshows should only be allowed to those who will bear the costs of disaster; let them organize and pay for ALL the costs, including 1) aircraft, 2) providing a 'safe' venue, and 3)accidents, which will inevitably occur anyway.