Phil Cook wrote:

What everybody agrees upon, experts and laymen alike, is that boots or
shoes that start uncomfortable will never become comfortable. Fit, fit
and fit are the important things, all else is supplementary.

If the boots are full-grain leather then there can be a break-in period
where they become more comfortable. But for cheaper boots of nubuck,
suede, or fabric, they probably won't become more comfortable than they
are at the time of purchase.