The number of people working in SLOT XO Cardiff city centre is 50% lower than before the pandemic, according to research.
A study by the The Centre for Economics and Business Research (CEBR) found the city had a lower share of workers back in the office than four other major UK cities.
It found some £400m less had been spent in the city centre since March 2020.
The Welsh government said it recognised the "big impact" of Covid and was working closely with sectors affected.
A review conducted for Cardiff council found the shift to home-working has had "a radical impact" for cities, but added many suggestions about the longer-term had been "premature and shallow".
The CEBR research concluded spending in shops and food and drink establishments would be about £6.3m less per month than at the start of the pandemic, if workers in Cardiff worked from offices for an average of two days per week.
However, the financial impact on Cardiff was found to be lower than London, Manchester, Glasgow and Newcastle, the other cities featured in the study.
Zipporah, a Cardiff-based IT company which provides resource management software, decided to move from a large site on an industrial unit to a smaller office space last year after finding home working was more useful to its employees.