I have some non-zero level of expertise in on-line shopping, although it is close to zero. Nonetheless...
Based on people I know who do LOTS of on-line clothing shopping, it works if you accept the trade-offs. Many, for instance will order 10 items knowing that 7 will be boxed up and returned. Once you get used to the routine, in the end it is less of a hassle than say going to the mall. You learn how various brands are sized and end up returning less as the learning curve grows. Free returns are common, often from your front steps.
I bought my last pair of tennis shoes on-line as brick and mortar stores don't carry them. They fit! I tried on and bought a pair of running shoes, liked them and got more of the identical shoe on line. This is my non-zero experience. So far so good.
Take the plunge, order a bunch of stuff, return some or all and repeat. If you hate it after that, well, the shirts and pants you have are probably just fine for another year. It's not like we can go anywhere anyway.