Competitors
One bright spot for Adobe is that, while their challenges and risks are manifold, they are not any worse what their large enterprise competitors Oracle, Salesforce, or SAP face too. Let us not forget that their “complete solution offerings” are also largely the result of acquisition, that many of them also rely on older technology, and that they too are not always “seamlessly integrated”.
Oracle relies on ATG, a company they acquired back in 2010, for eCommerce. I recall doing ATG projects back in 1998 at the height of the dot-com boom. SAP acquired hybris back in 2013 and the Salesforce Commerce Cloud is the re-branded Demandware, acquired in 2016.