The Will of the People
In 2014 there was an all party consensus about having a referendum - everyone agreed including the parties who planned to campaign to remain part of the UK.
2022 is very different - there is no all party agreement, all the opinion polls say Indyref2 is not a priority and, of course, at the 2021 Holyrood elections more people voted for parties which oppose a referendum at this stage.
If they could the SNP/Greens would ignore popular opinion and rely on a fleeting parliamentary majority at Holyrood to impose their will by a simple majority vote.
So the timing of a future referendum, the question (Remain vs Leave or Yes vs No) etc etc would all be decided by what best suited the SNP/Greens which would be unfair and autocratic.
Thankfully, the SNP/Green machine do not have the power to decide these important issues for themselves - they need agreement from the UK Government's to trigger another referendum and that will only happen when it's clear the Scottish people want it to happen.