As other have noted, splitting is a natural process of beekeeping.
however, I've noticed a discernible change in the beekeeping profession in the last 10 years.
To take a step back - there is a huge variation in bee characteristics from hive to hive.
What I've noticed is that package and nuc suppliers (aka bee breeders) are far less likely to treat hives. And it has become near impossible to buy 'traditional' chemical bee disease medications.
The prevailing modus operandi these days is to leverage natural evolutionary processes. I.e. let weak hive fail and therefor let undesirable genes phase out.