A priest once said to me "Funerals are for the living, not for the dead."
They are to pay your respects, either to the deceased, or their family, or both.
I would have no objection to the funeral with cyclists. I have been to a funeral where the coffin arrived on a motor bike. The deceased had loved motor bikes. Also, I have been to funerals where there was a cavalcade of classic cars and funerals attended by the local football club, wearing their kit. They were all an acknowledgement of the deceased and their interests.
I am pretty gobsmacked that most men don't own a suit nowadays. Men in my family own a variety of suits. However, a dark tie, white shirt and dark trousers are perfectly acceptable. I am amazed, considering how many clothes most women have, that a number of women don't own suitable clothes for a funeral. I thought everyone owned a pair of black trousers. Wrong again.
I would also have no objection to someone arriving in their working clothes, if it was a quick 20 minutes and they were going back to work. To attend the service and reception in paint covered clothes, for a couple of hours, is a bit off. It's fairly normal for folk to say ' sorry, can't stop, gotta get back to work, but I felt I'd got to say my last goodbye '
The thing that annoys me is that people don't know a single hymn. They just stand there in silence during hymn singing. Luckily, I come from a family that does know hymns and all sing. I have been to many funerals where I have been the only one singing. Maybe I will have swing low sweet chariot at my funeral. I have already planned the reception.