what does 7 transactions per second mean?

judging from below image i took from

https://preview.redd.it/ud6qfllcgjgb1.jpg?1200&format=pjpg&auto=webp&s=ae55e928561180a9ee75a70f350d97505769352c

the throughput is 7 people per minute, but the bus is not carrying 7 people per minute, it is carrying 7 people per 60 minutes. it takes 60 minutes for the 7 people to reach destination.

can someone explain why is the capacity of the bus 7 per minute and not 7 per 60 minutes?

thanks

edit:

also, what does it mean why a transaction need multiple confirmations? once the people reach the destination should only need one confirmation. no ?

edit:

lets say i have 8 transactions executed at exact same time and each transaction needs one confirmation. i need 10 minutes to receive the bitcoin transfer [ equivelant to number 3 above]

at the beginning 7 transactios willget executed and one will have to wait 10 minutes to become executed. so in total, for the 8th transaction to be received i must wait 20 minutes.

is this right?

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