Yes, therapy has been shown to be
effective.
Academic studies have found that
people are better off following
therapy (https://www.apa.org/about
/policy/resolution-psychotherapy).
A Consumer Reports Survey from
1995 showed that roughly 90% of
respondents found therapy to be
helpful (https://pubmed.ncbi.
nlm.nih.gov/8561380/).
Research also indicates that for
many issues and problems,
therapy is just as, if not more,
effective than medications (https://www.ncbi.nlm.nih.gov/
pmc/articles/PMC8475909/).
In addition, a study by Ken Howard et al. determined that 75% of individuals receiving therapy showed improvement after 26 sessions and 85% showed improvement after 52 sessions (https://i-cbt.org.ua/wp-content/uploads/2017/11/Howard-dose_effect-psychotherapy-1986.pdf).