One doesn't necessarily "sidestep fashion" by dressing conservatively. Desired lapel and tie widths change over the years.

I agree with both of those sentences, but I think the conjunction is odd.

There is fashion in lapel widths, but that fashion is, I think, for people who have to wear jackets, for whom jackets are thus not conservative. For such people, there are conservative (ie, low-risk) widths. For people who don't have to wear jackets, lapels may matter, but they'll matter in a very different way.

For settings where a wide range of clothes are allowed, there are options that are low-risk and slow-changing. These usually involve dressing up a little, but not too much. I think people trying to avoid fashion underestimate the risk, ie, the residual details that matter. Also, there's some other mistake they make...maybe overdressing out of confusion of different meanings of conservative?