GJ-11 was "in service" since 2019 and look how long it took for actual deployment. IOTE counts as in service as technically they are delivered to the airforce for evaluation but are still far from serial production and front line duty.
and IOTE models still do represent the very first in service variant.
The UADFs shown in the September parade are technically in service. They most likely represent IOTE level of service so you can't exactly compare them to the J-20. The J-35s are also both in service and likely not far beyond IOTE if even passed IOTE. However, we wouldn't call those J-35s prototypes or even late EMD prototypes.
The GJ-11 in 2019 was probably IOTE and PLA never talks or shows much of anything that's in IOTE outside of mockup or a few photos. J-35 carrier variant is heavily propagandised so we see a bit more of it. Most non-military people only see "big" things like carriers as a milestone. In the case of J-35, stealth fighter on EMALS carrier.
UADFs are in service too. Wait some time and the first official variant will just be Type x then comes Type xA and so on. If not skipping the first level and these UADFs are the Type x and in some time they will be replaced by Type xA.
All of these are certainly in service just like 2019 version of GJ-11 was also in service in training, evaluation and tactic forming role. The GJ-11 we see today is a later block variant of the 2019 version. We're only seeing glimpses of these even though they're being mass produced.