I do this for a living and no, most office towers from the last 50 years are not ripe for mixed use living. It can be done, but the unit economics are sobering.

Historic buildings lay out well, but it's still very expensive. We are converting a historic building in downtown St Louis right now opening in June, and it is very expensive, historic tax credits mandatory to make the numbers work. Shameless plug: www.victorstl.com

Very expensive to convert the space, different utility demands (many more bathrooms), mechanical ventilation needs are very different, office towers have very high opex, requires a team to run them, and typically have exorbitant RE taxes.

All that for the privilege of a sub-par living experience, i.e. rents will be low relative to market. severely limited daylight, no balcony or fresh air (windows aren't operable).

Many office towers and their associated leases were vanity projects for corporations wanting high profile space in a high profile areas to attract employees and prestige, but business culture has, in large part, moved on.

My small business moved from the "elite" downtown high rise to a boring little office park closer to our team's homes, and nearly every aspect is significantly comparatively better. Shorter commute, no high-rise elevator wait, no walk to the garage (and another elevator and wait to congestion to exit at quittin' time), no panhandling when you want to step outside for fresh air. I do miss the high rise view, but otherwise my office and business functions exactly the same, with the added perk of being able to make it to my kids' activities whenever I want.

Elite is no longer "main and main hi-rise" but working wherever you want whenever you want. Elite is Zooming in from an Aspen CO ski lodge. Has been for some time, but the daily expectation for in-person meetings has been cut. Now, revisit the high rise calculus again...