Strange title. The obstacle to "replacing JavaCard" is not the availability or non-availability of some software stack but the fact that JavaCard hardware only runs Java, and the manufacturers that make such devices continue foisting it on people.
This appears to be discussing the use of a software platform on a non-smartcard chip; an ordinary MCU with some MCU-class security features. This doesn't reflect the level of physical hardening that, as far as I am aware, actual smartcard chips have, so it seems strange to make a comparison to JavaCard. (The lack of programmable smartcards other than those which force one to use Java has long been of irritation to me, as I previously wrote about. [1])
AIUI this situation has now changed and there are now flash-based (rather than ROM-based) smartcard chips which use an ARM core (SC000) rather than an 8051 as they often did, but these chips all appear to be NDA-encumbered, making them DOA for my purposes. Whereas ordinary MCU chips lack the same hardening.
[1] https://www.devever.net/~hl/smartcards
