To sow an alternative lawn?

This is the very thing that I've been pondering OP, I only have a small lawn as I keep cutting bigger borders into it! I think this summer watching the blackbirds sadly trying to peck for worms in a dustbowl has tipped me over the edge
There is nothing really like a lush lawn to set the garden off but I think those summers are in the past, so I also like the idea of thickly mulched pops of ornamental grasses & bulbs & happy birdies scroffling through it all!

It's actually a good idea as it's likely future summers will also be subject to longer dry periods, so finding an alternative makes sense. Clover does withstand drought better than grass does in that the leaves remain green for a lot longer, where grass simply hunkers down and waits it out - the top leafy growth dies back but the plant remains alive until normal conditions resume. Clover also has lovely flowers that are helpful for pollinators, while grass does not (grass is wind pollinated when it's allowed to flower).

My own lawn has land drains because it's prone to winter flooding as we're on clay soil. The grass dies back first above the land drains so I have bare brown stripes, soooo attractive. I now have patches of clover in places and they have coped better with the drought. I won't replace the grass with clover because it doesn't bother me enough, but if you want more reliable green, I would do it.

You say it kills off the lawn - but it does recover once the rains come again surely? You are not having to resow every year are you? It goes all dried up and brown but it will grow back.

Having said that I see nothing wrong with having an alternative so why not. Could look nice. Clover, camomile, wild flowers even.