Yeah, the lads above have pretty much covered it.
A 'Cherry-picker' would normally only be used if the pole is deemed un-climbeable. There's a variety of reasons this could be such, including being out of the 13yr test-cycle, no test label on show, low wires, a designated 'D' Pole (Dangerous), to much 'furniture' at the pole top. There are other categories as well such as 'H' (Hazard) Poles, 'SD' (Shallow Depth) poles …. etc ….. but the engineer has the last say in whether he climbs or not. It is down to his own personal risk assessment at that time, even if all other measures are met.