Tailors are a niche thing for weirdos, now. It's not exactly a growth market. Most folks only wear a suit to weddings and funerals, and maybe job interviews. They have basically no need for more than two suits, and many try to get by with just one (in black, probably). Lots don't own one at all, maybe just a cheap fused-construction blazer or two, if even that. Outright bespoke clothes are a niche of a niche.

Normal people wear clothes containing minimum 2% elastic and perhaps never, ever visit a tailor in their whole lives, except maybe one at a tux rental place or a wedding dress store, for their own wedding. If they repair clothes, it's sewing on the odd button at home or using iron-on denim patches. Past that, it's just not worth fixing, normal folks' clothes are so cheap.

The whole market for tailors is practically an affectation. It's not serving much actual need any more, not from the perspective of the overwhelming majority of people who are happy with stretch-denim jeans and polyester sportswear jackets and such. It's basically 99% of the way to being an obsolete job, kept from total death by a few enthusiasts. Only a bit more lively than the market for, say, authentic regency-era footwear or something like that.

(I am a fellow weirdo, for the record)