Short answer: yes. A listing without a phone number loses the single biggest action mobile customers take, which is tapping Call. The real question is which number.
A dedicated number costs little or nothing: a second SIM, a VoIP line, or a free forwarding number that rings your cell but lets you keep the two lives separate.
Plenty of one-person shops do, and it's fine as long as you go in with eyes open: set a voicemail greeting that names the business ("You've reached Mike at Mike's Tires..."), because a generic "leave a message" greeting makes people assume they misdialed and call the next shop.
The number on Google, the number on your website, and the number on your invoices should be the same digits. Mismatched numbers confuse customers and make Google trust your listing less.
Any public number attracts some spam, which is the argument for a dedicated line you can filter. It's the cost of being reachable, and being unreachable costs more.
Careful: the number on your listing should stay consistent long-term. If you use tracking numbers, use one dedicated tracking line for Google permanently rather than rotating numbers.
Both. If your line can receive texts, turn on the chat option so a customer standing in a loud shop can text you instead of calling.
Rather have someone who does this every day handle it? That's the $75/mo plan. Or keep going solo, that's the whole point of these guides.
The straight answers Text Nick