Hi there!
I have some smart electrical plugs that I can steer via Alexa today, but the supplier / service provider (OSRAM) has announced that they will discontinue their service. It is possible, however, to use the plugs with another ZigBee smart home gateway. I don’t have one yet. Can anyone recommend generic ZigBee gateways? (I know I might use Philips Hue, but it’s twice the price and offers functions I don’t really need.) Thank you in advance! 
I’ve not used it, so in no position to make a recommendation, but the only “brand name” out there that I even recognize that hasn’t already been marked undesirable or even EOL is Hubitat. I have to wonder if the eventually forthcoming Apple/Google/Samsung/everyone else tieup Matter (formerly known as CHIP) is causing disruptions in this market.
If you’re wanting to invest some time then home assistant offers the best long term support for ZigBee. Personally I use smarthings for my ZigBee kit a(I run my home assistant in a VM so a USB ZigBee adapter wasn’t reliable enough).
Smarthings has always been rumoured to become a paid service but that’s never happened so far and they have just announced a big upgrade to their online tools.
Tuya seem to be the flavour of the month but I don’t know if they are compatible with osram.
Thank you, both! I have taken a first look a these solutions and it feels like falling down the smart home rabbit hole. 
It’s an interesting idea to employ one of the running Raspberry Pis and give it double duty as a home assistant access point…
Getting started in smart home IoT makes everything so easy, so plug-and-play that it’s interesting to awake to the opportunities to do this more from a DIY angle.
Just had a thought that if you have any of the newer echo devices, then some of these have zigbee hubs built in.