Until a couple of years ago, AMD was in survival mode, fighting Intel on one side and Nvidia on the other. Two rivals that were making money hand over fist while AMD was bleeding money.
AMD picked open standards and made investments on open source frameworks and libraries commensurate with their financials, the hope being that the community could help pick up some of the slack. The community, understandably, went with the proprietary solution that worked well at the time and had resources behind.
The net results is that the Nvidia ecosystem has gained a dominant position in the industry and benefits from being perceived as a quasi-standard. On the other hand, open source efforts by AMD or others get viewed as "not serious".
The financial situation of AMD has improved somewhat over the last couple years. So AMD is "taking AI more seriously now". But it might be too late and the proprietary ecosystem has probably won.