This is only an American issue as the populations of most other countries (especially France) do not shower that often.
There are precedencies shown in the Talmud to allow stringencies of these rules to be adjusted as for Americans who are considered “istanis” in these matters. Chazal would permit leniencies to people who are sensitive concerning their bathing and eating requirements (istanis); i.e., an istanis mourner was permitted to bathe.
Rav Dovid Kronglas allowed showering during the nine days but advised bochrim to increase the cold water each day as it got closer to Tisha B’av.