First of all, no, both sides use FPV like drones as suicide drones. Here is just a few example videos. You can find literally dozens more like these.
https://www.reddit.com/r/CombatFootage/comments/13qdumi
https://www.reddit.com/r/CombatFootage/comments/13t49ri
https://www.reddit.com/r/CombatFootage/comments/13us1ts
https://www.reddit.com/r/CombatFootage/comments/133t7jc
https://www.reddit.com/r/CombatFootage/comments/12zftlr
Secondly, you're looking at it just by the cost of the drone itself, which is the wrong way to look at any type of munition in a war. In the videos I shared above, you can see they used these FPV suicide drones to attack soldiers, different types of armored vehicles and even tanks. Drones that drop grenades have to adjust and stay still, these things are flying grenades or cluster bombs themselves, finding their targets and then attacking them at 140 km/h. Perfect for taking down targets of opportunity and great ROI when you consider how cheap these drones are. I mean, partisans even used FPV drones to successfully attack Russian A-50 awacs, one of the single most important equipment for any modern military force:
www.reddit.com
www.reddit.com
Third, you're wrong again, as you're thinking only of Switchblades. Ukrainians have been building their own kamikaze drones for months now:
A Ukrainian military-intelligence unit is building a fleet of "first-person-view" drones for surveillance and to carry out attacks.
www.businessinsider.com
Here is a more recent report on it:
Ukrainian blockchain company Everstake has supplied 500 Pegas FPV "kamikaze" drones to Defense Forces, who already use those to destroy enemy targets, Deputy Prime Minister for Innovation and Minister of Digital Transformation Mykhailo Fedorov reported on 30 May. "500 Pegasus FPV drones from the...
euromaidanpress.com
With a direct quote from a Ukrainian minister:
As I said before, these things are perfect for spotting and engaging targets of opportunity unlike drones that drop grenades which has to correct itself and stay still beforehand. Both has a place in the modern battlefield, just not the same place. Grenade/mortar dropping drones are more effective against enemy that is entrenched or otherwise staying still.
And finally, if that was the case, no military on the planet would invest in loitering munitions or kamikaze drones of any kind. But that isn't the case at all because nobody is looking at the cost of these kamikaze drones or loitering munitions like Kemankeş in isolation.