Magento gets sold again

After being bought by eBay back in 2011 for a rumored $180M then sold off in 2015 to private equity firm Permira Holdings LLP for $200M, Adobe has now purchased Magento for 1.68 billion.
Yes, you heard that right.  Adobe bought Magento for almost ten times more than eBay paid for it seven years ago. 
Is it worth it?  Only the future will answer that one.  But with that kind of money in play just where is Adobe going with Magento?
While Adobe hopes this step will allow them to compete with Saleforce and Oracle, it begs the question of the openness of Magento and the future of the community edition.  Saleforce and Oracle offer proprietary eCommerce solutions which the opposite of open source.
Can Adobe really compete while its solution is open to its competitors – no need to beg, borrow or steal when every line of code is there to be read.  And just what is behind their planned share buyback?