A quick google showed me that Paris has 18,000 registered taxis, so this is around 3% of them.

The taxi market is in my view a great opportunity for expanding fuel cell cars, as Paris might represent only a percent or two of the total taxi market in big cities around the world.

FCEVs are clearly superior solution for this market to BEVs for a number of reasons:

Charge times - whilst you are charging, you are not making money.

Cold weather performance - minimal range loss, and plenty of power for AC in hot places too.

They address the biggest source remaining of emissions as the fleet turns around, and older vehicles are retired, which is non exhaust emissions;
https://www.greencarcongress.com/2019/07/20190714-nee.html

'Data from the UK National Atmospheric Emissions Inventory indicate that particles from brake wear, tyre wear and road surface wear currently constitute 60% and 73% (by mass), respectively, of primary PM2.5 and PM10 emissions from road transport, and will become more dominant in the future. Currently they contribute 7.4% and 8.5% of all UK primary PM2.5 and PM10 emissions. Therefore to achieve further gains in PM2.5 and PM10 air quality in relation to road transport sources requires attention to reducing non-exhaust emissions, not solely a focus on lowering exhaust emissions.'

(see also graphs on link)

Now I don't entirely go along with those figures, as they ignore for instance the huge emissions of diesel cars in their cleaning cycle, so you end up with fake figures overall just as the zero rating in Europe for charging a BEV is utterly fake.

But nevertheless non exhaust emissions are an issue of increasing importance which since they filter the air FCEVs leave it cleaner in cities than before they passed by, whilst BEVs turn out loads of particulates, even though they have regenerative braking, which of course FCEVs also have.

Servicing for Toyota's FCEVs has proven to be simple and tthe reliability in fleet use is as good or better than the legendary Prius.

It is not even mentioned now, so I don't have a recent link!
But that is in itself significant.

Both Green Tomato in London and now Hype in Paris after extenisive experience are expanding their Mirai fleets, with none of the fleet issues due to unreliability that have hit Tesla.

Of course, the big limit is infrastructure, but the taxi market in itself seems to be large enough to act as a considerable driver in expanding that.

It also helps that the Mirai replacement is a 5 seater.