What jobs, careers or professions used to be in high demand , extremely profitable and essential 50, 100 even 200 years ago, but today are completely redundant or non-existent?

Computer. Because we have computers to do that now.

Those people who used to type 100+ copies of the same memo all day long, because there weren't any photocopy, or mimeograph machines at that point.

Switchboard operators are (mostly?) gone.

Travel agents are a rapidly declining group.

Horse-shit street cleaner.

these two have been long gone but ice companies and pin setters.

back before freezers, you had an ice delivery guy come by and drop off ice for you. They got their ice from frozen lakes.

Pin setters did what the automatic machines do at bowling alleys today. My great grandma once told me it was a terrible and dangerous job, because assholes would chuck bowling balls while you were still standing there... she said she saw several people get their ankles broken.

there are still people who make and fit horse shoes and chimney sweeps. doctors are still around.

A bunch of them.