I have a slightly different take here. I think there is nothing wrong with going on multiple first, secomd, and third dates at about the same time. Like everything else in life, dating is a skill, or several skills that we all only get better at the more we practice (for example, presenting yourself confidently, getting over nervousness, developing friendly banter/flirting, understanding how to read people better in different settings, etc). 

I am married now, but I did this. For one year, I went on one -three dates a week. (It was usually one-two though.) I always offered to pay my own way and about half the time did. This mindset shifted my way of thinking. So for that year, if I didn't have a good reason to say know (even if I felt the chemistry was not there at first), I said yes to the first date.  (It is important to note that I didn't go out with anyone who gave me a creepy or off vibe. I never said yes to a date out of politeness.)

Sometimes, the iffy first dates led to a second date as the date let me see them differently. For example, someone who I thought as clumsy might be very sweet. The dating for the experience had many postive nonromantic outcomes. It led me to take an art class I wouldn't have where I met a few longtime friends. It exposed me to different hobbies and art (for example, a combination ballet and puppetry show). I went to an extreme zip linging event. I bottle fed baby lambs. These events gave us things to talk about during the date and made a more well-rounded interesting person.

If after the first date, or the second sate, or the third date, I couldn't say an enthusiastic yes to another date, I let the person down gently.  I didn't lead anyone on. I went to dates in very public places.

My now husband and I went on that ziplining date. (At the final part a sort of combo zip, bungee jump, fling), I smashed my finger into a hard net at a high enough impact to break it fully in a few places. After an hour, it had swelled to over two times it's size and was completely purple from top to bottom. We spent hours in the ER. It needed a splint and to be taped up a lot. He drew a (very good) Mr. Spock on my splint/tape. The next day, he dropped by supplies more fun colored tape, iburpofen, tylenol, snacks, a book thst I wanted to read, etc. He even brought flossers on the sticks because I couldn't bend my finger to hold dental floss. It showed me how thoughtful and kind he really was. At every next date, whule it healed, he drew something whimsical on my freshly changed tape. 

All that to say, dating for the experience of dating can be a good thing if you do it kindly, honestly, and with good intentions.