I wouldn't. Cost to make a device "smart" is much less than $1 in parts, app and infrastructure are not rocket science and even with no evil intentions you get very valuable data on usage, what breaks first, environment, location etc. Seems like a no-brainer.
Those will soon also not require you to connect them to your wifi, NB-IoT both chips and plans cost for businesses are already very good.
Thanks to Tuya, the software and infra side for making a garbage-quality IoT device is effectively free now. You may be surprised just how much of those you have around you. Any random device class that suddenly gained optional "control through app/voice assistants" feature is likely Tuya in disguise - magic of white-label IoT.
Sure, touchscreen is expensive, but if you just have notification on your phone that the door is not closed properly that's already considered "smart". Basically anything connecting to your home network is advertised as such.
Those will soon also not require you to connect them to your wifi, NB-IoT both chips and plans cost for businesses are already very good.