The Submarine Matters article France's Innovative Submarine Industry eg. Scorpenes of August 11, 2023, prompted an avalanche of comments from August 11 to 15, 2023. I won't attempt to address all issues raised, but some of them.
French Naval Group's (NG) Scorpene SSKs (17 sold to 4 customers) are more equivalent to German TKMS' non-AIP Type 209s (90 sold to 15 countries). The Scorpenes and 209s are capable and less expensive than Type 214s (whose relatively expensive AIP tends to be for specialised uses like missions in the Yellow, Black, East China and Mediterranean seas).
Whether NG (with a conventional Barracuda), TKMS (Type 212CD E) or Saab (with its C718) are likely to win the Netherland's Walrus Replacement Competition, winner perhaps announced in 2027, is anybody's guess. Much depends on the Netherland's Navy and broader Dutch government's requirements, which are complex, confidential and perhaps even changeable as differing technologies mature.
Countries with long submarine building histories and whose submarine forces are all conventional (particularly Sweden and Germany) have some advantages in submarine and AIP design and industrial focus. This is compared to countries attempting to build conventional and nuclear subs (like India and Russia, both with no AIP) or France with an all nuclear sub navy while only building conventional subs for export.
China is an exception building nuclear subs (own navy) and conventional subs (for own navy and export) and China has developed second generation AIP and is exporting AIP conventional subs.
Medium sized concept submarines without a fin/sail haven't sold well in the last hundred years for reasons of sea-keeping, safety, command, navigation and security - all especially in the surfaced approaches to and from port and in emergency ascents.
The issue of submarine customers choosing Lithium-ion or Lead-acid Batteries and AIP is very complex. The distances and mix of missions a customer expects are relevant. Also is the customer country building its own, exporting or importing subs? Economies of scale, money available and whether the customer is also developing nuclear subs all come into it.