(1) For decades and even now Muslims think telescope sighting is not valid, but Ulamaa' (Scholars) accept it now valid for starting Islamic months.
(2) Translation of Quran in any other language was prohibited by Fatwas till about 1000 AD. Now Ulamaa' allow it.
(3) 300 years ago, when clocks and watches were invented; use of those devices for prayer times was not allowed by Ulamaa'. Now they allow it.
(4) 120 years ago, in India, calculated Prayer Times were not acceptable per Fatwas by Ulamaa'. Now they allow it.
(5) 60 years ago, loud speakers use for Prayers was considered Haraam, per Fatwas by Ulamma' in Indo-Pak. Now they allow it.
(6) 50 years ago, taking picture for ID or passports was considered Haraam, per Fatwas by Ulamma' Now they allow it.
Now, all of the above is considered, not only allowed, but people don't even know that these were not allowed before. Why, it takes decades for Ulamaa' to accept such things?
Some of Our Ulamaa were reluctant to do Ijtihaad for new things; Are the doors of Ijtihaad closed forever??