Open house realtors dont take no for an answer

been to a few open houses the past few weeks and I'm getting spammed by multiple ones. I've told them all im just looking and not ready to formally look for a house or work with a realtor, but nonetheless they text me to check in and have added me to email lists spamming new homes. One even told me I need a strategy and plan and should become more serious about looking lol

I'm giving fake info from now on when I visit open houses and sign the sheets.

Also, I remember in the past the listing agent or someone from their office would host an open house - now it seems like there have been agents who dont even know the listing agents and arent in the same office, what is with this change?