Struggling amidst a declining economy and a failure to handle the COVID pandemic, Erdogan is experiencing a loss of support, and, taking a leaf from the Donald Trump playbook, is trying to consolidate his voter base among religious conservatives to hold on to power. Erdogan has seemingly made similar moves before, from the re-designation of the Hagia Sophia as a mosque to efforts to distance Turkey from Europe, all are designed to cement his legacy and court religious fundamentalists. Technically speaking the withdrawal from the Istanbul Convention in this way is illegal (unconstitutional via presidential decree), in spite of this Erdogan's justification remained that the convention “was hijacked by a group of people attempting to normalise homosexuality" [1], an answer clearly based in homophobic pandering more than reality.
english.alarabiya.net/News/middle-east/2020/11/03/Turkish-support-for-President-Erdogan-s-AKP-party-hits-all-time-low-Poll washingtoninstitute.org/policy-analysis/erdogan-make-hagia-sophia-mosque-again-will-it-help-him ekathimerini.com/opinion/interviews/1156642/erdogan-is-shifting-turkey-away-from-europe-former-president-tells-kathimerini [1] aei.org/op-eds/why-turkeys-istanbul-convention-withdrawal-will-backfire