Not related actually.

Bond yield is always following the interest rate environment.

If FD rate out there is 3.5%, then most retail good rating bonds out there are priced at yield 4.x% to 5%.
So interest rate is not a primary issue.
Bond yield generally is always trading at least 50~100 basic above interest rate depended on their quality or rating.

Retail bond market that lack transparency and liquidity (aka you don't know how much current transaction price is), which may be one of obstacle for retail bond market to develop.
Also, retail bond market with high barrier that need at least 250K per investment, also a stumbling block for ordinary retail investors.
As generally for small retailer invest a single bond of 250K, as if the bond default afterwards may mean entire 250K in jeopardy.

For retail to participate in bond, the better way still through bond fund, or ETF, as it provides better diversification.