I was surprised to get reminded that of the 18 bikes I’ve owned in 30 years, I actually tested 7, as they were LBS purchased. It helps to live in an urban area where the shops keep stuff in stock and that I’m not an odd size. It also helps to know what works and to be able to order and build up frames.

Personally and if I couldn’t get support from a shop to not require an up front purchase, I’d get fitted (and pay for it), then go online.