Ocean Purpose Project interview questions

I wrote in to express my interest in working for the company. I received a response after one follow-up. I was sent an assessment with the expectation that I complete it in the following days, although the period overlapped with a religious holiday weekend. In other companies I'd worked for, the assessment would be set after, at the very least, an initial chat with the hiring manager. The hiring manager would also check in on whether I had the capacity to complete the assessment in the allotted time, before sending it. I feel that this is basic professionalism. Either way, I completed the assessment (a full communications strategy) and sent it in on time. However, I was ghosted despite repeated follow-ups. I don't mind being rejected, but I feel that the organisation had wasted my time. I wasn't even offered any feedback on the assessment.