Indeed.
The bubble memory was doomed by the fact that it had to be made from material that was patterned, by using photolithography or similar means.
Because of this, even if its structure was simpler than that of semiconductor memories, its bit density could not be increased much over that of semiconductor memories and its fabrication technology was not significantly cheaper.
Being much slower than random-access memory, while not having much cost advantage, made it non-competitive.
In contrast, the memories that use a homogeneous recording material with bits defined by the movement of a recording head, in the form of disks or tapes, compensate their slowness by having a much lower price per bit.
Thus bubble memories were too expensive in comparison with HDDs and too slow in comparison with DRAM, so no application remained for them in a computer that used DRAM and HDDs.
Flash is patterned. There is talk about patterned surfaces for HDD but who knows if it will ever see the light of day.
Which is why flash remains much more expensive than HDDs.
Flash is also much faster than a bubble memory, because it provides random access to blocks, even if a block is read sequentially. Thus flash was positioned in a good spot in a hierarchy of memories where a compromise is made between access speed and cost per bit.
To achieve a similar speed, a bubble memory would have to store a block, e.g. 4 kB, per bubble ring and have a huge number of bubble rings (i.e. billions, to compete with the current flash memories) to which random access would have to be provided by semiconductor ICs handling the multiplexing and demultiplexing of data.
Due to mixing ferromagnetic and semiconductor technologies, it is very unlikely that such a device could be made at an acceptable price.
Flash only got competitive after both HDDs and DRAM scaling slowed, allowing it to catch up, and end up in an interesting position between them.
There are about a dozen upcoming memory technologies with better theoretical headroom waiting in the wings for DRAM and Flash scaling to slow down. In the early 10's it really looked like Flash was about to be replaced, but then Samsung managed to move Flash to the third dimension. Very soon, either DRAM does the same, or it gets replaced by something.