Why do some shows use hand mics and others don't?

I notice on BGT Ant & Dec have hand held microphones, carry them around and only appear to use them to talk to the acts - not for the regular presenting duties. I presumed as well for talking to the acts they were back-up mics in case the regular ones packed up.

Think it was either Sports Relief or Comic Relief a few years ago and some dance act had a microphone failure with one of the members on the over-the-ear microphone, so cue runner with hand-held microphone as a replacement and some clapping choreography that looked clumsy because the mic was in the way...

I recall on some football with Adrian Chiles a couple of years ago they had some sort of failure, meaning they had to resort to stick mics, they had one for Adrian and one for all 3 pundits to share, so they had to keep passing it between them.

Having on stick mic for the host and the interviewee, like seen on some live news reports, is clunky as they keep having to remember who to point it at and they tend to miss the first part of each answer.

Yes, Fiona Trott is one reporter who can't seem to grasp that concept !

Something similar to this was posted previously - The Chase Russia with massive stick mic and the presenter is clearly struggling to keep everything off the floor here:

Very much doubt it was a runner. Far more likely to be a Floor Sound Assistant (or in some cases FM or AFM) or similar. Wouldn't be a runner duty in a normal studio set-up.

Normally the sensible approach in that situation is a personal mic for the reporter with a reporter holding a stick mic predominantly to talk to guests. (You then also have a standby mic for the reporter as a bonus)

That was the set up on the Big Breakfast OBs, Cheggers had a personal mic and a hand held for interviewing.

On at least one occasion the hand held failed, so for the next hit the personal was gaffa taped to the mic flag on the dead hand held.

The X Factor and I think Britain's Got Talent have switched to desk mics as used in the US version over the last couple of years after using presumably lapel mics for most of the last decade. Any notable benefit to this or just Simon making changes where changes didn't need to be made as usual?

There was a technical problem on This Morning several years ago when the sound desk crashed, so both the presenters and guests were forced to share two lapel mics between each other before it was decided to take the show off air.

Some talent don't like wearing personal mics with radio packs for comfort/style reasons. Some don't want to be heard off-camera discussing things, so take their mics off during breaks or when off-set to ensure privacy. However if they do that there is a risk they won't get them back on in time. Having a desk mic avoids a lot of this.

Very interesting !! I wonder if UTV or STV went for an ad break ? ITV themselves clearly didn't

Also, why is he reading the questions from cards when the podium is still there?