Over on Guru3D we saw a post suggesting AMD might abandon 32-bit systems. We are aware that NVIDIA has already abandoned 32-bit Windows as world+dog almost all use 64-bit operating systems now.
Given the move by NVIDIA its reasonable to expect AMD may follow suit. Microsoft maintains Windows 10 in both 32-bit and 64-bit but few users select the 32-bit version.
AMD only has drivers for 64 -bit Windows for their most recent video cards.
Cards with 4GB or more VRAM cannot be used with 32-bit Windows as there is far too much memory on the card to be recognized within the limited address pace.
With more and more video cards having 8GB or more VRAM, clearly there is a big need for a larger address space. The trend with video cards is moving towards larger and larger amounts of VRAM.
64-bit is needed to be able to use the memory seen on machines. Laptops for the last decade have had 4GB or more memory installed so 64-bit Windows is necessary to be able to fully take advantage of it all.
We have long used 64-bit Windows as we tend to use more memory than most due to the workload we impose on our machines tends to be brutal. We constantly push our machines to the limit in order to get more done in a given day. Its also the reason we get newer machines occasionally as new laptop machines can support more memory and the integrated graphics are slightly better.