The institutions buying Bitcoin play a very dirty game in the beginning, you may know that the biggest names try to throw down the image of Bitcoin in the market so that the price drops and they can buy Bitcoin for a cheap price as they want to invest millions of the fund they have. And once it goes down, they buy it via OTC and other methods and release a statement how good Cryptocurrency and Bitcoin is for future payment methods. Silly
Well, they wanted to profit from their trades so they will do everything possible to make it happen. I can say it is not dirty since it is normal to do evrything to get profit as long as they don't manipulate the market. Yes, they can implement strategies that can affect the thinking and decisions of traders but such strategy is normal in a booming market.
In my opinion, several factors have driven institutions to this adoption as you say... Among these I would say the recognition of the potential of Bitcoin as a form of diversified investment, the existence of institutional investment vehicles that allow companies and funds to function in the cryptocurrency market and greater regulatory clarity in some countries, as we have seen in several cases, Germany, El Salvador... On the other hand, the support of influential figures, such as businessmen, investors and financial leaders, has also contributed to the institutional adoption of Bitcoin. As prominent figures express their support and actively participate in the market, this increases confidence in Bitcoin as a legitimate investment.
No matter what it is the common ground is that they wanted to take advantage of the opportunity that the Bitcoin market offers. Their main goal is to take a profit and grow together with the industry. If they don't find any profit on the venture, I doubt they would even pay attention to Bitcoin.