Since the start of my saving efforts, I have seen about 6.7% rate of return which is not currently enough for me to start my retirement life quite yet.
• $244k in various Vanguard index funds (portfolio currently 79% stocks, 21% bonds)
• $192k in traditional IRA
• $26k rainy day savings account
So, your invested assets are a total of 436k, which is great (I'm not counting the savings account). Your rate of return (6.7%) doesn't really mean anything for the purpose of asking "am I ready to retire?".
If you are set on the 40k ER budget going forward, you actually care about the withdrawal rate and if that is enough to cover your expenses:
40k * 25 (considering a conservative rate of withdrawal of 4%) = $1,000,000
You need a net worth of at least 1 million to sustain 40k per year expenses. You are almost halfway there, but that means you need to either continue with getting another 9-5 job with high pay so you can squirrel away money faster, or take a lower stress job that covers your current expenses so you can be totally hands off of your nest egg until it grows on it's own to 1 million. Hope that makes sense.
So:
1. see what you can cut from the 40k sustainable budget, its much easier to save $850k (yearly expenses of $34k) than it is $1 million ($40k). Your current nest egg gives you a 17k yearly budget, so unless you are willing to more than halve your yearly budget you won't be able to sustain yourself with your current nest egg. You are almost halfway to FI, so congrats!
2. you do need to save more by either actively contributing to your stashe or being completely hands off of it while it grows on its own to the point you need, no touching it. Regardless, this does mean you need some sort of income that at least covers your existing expenses if not more. The more "extra" you bring in, the faster actual financial independence will come.