And arguably for the past 10-15 years.

FINAL AP RANKING:
2015: #7
2016: —
2017: #2
2018: #8
2019: #4
2020 Currently ranked #1

Only 3 teams have finished in the Top 10 of final AP Poll each of the past 3 years: Carolina, Duke, Gonzaga;
Over past 5 years only Duke and Gonzaga have finished in Top 10 of the final AP Poll four times; and finally
Gonzaga is the only team to make the Sweet 16 each of the past 5 years

And there's a strong argument they were already a Top 5 program before these past 5 years (2005-2015)
The big asterisk will always be they still haven't won the Tournament, but really in the past 15 years they've surpassed nearly every program except Duke, and they're pretty even with them in terms of overall success.
Absolutely unbelievable what they've created and sustained. I don't know anything else you could compare it to.