What is fueling AI bubble? When will it bust?

The stock Index in USA and Asia has been rallying despite the continuing strife in middle-east region and war between Russia and Ukraine on the basis that AI and technology companies’ earnings are booming and earnings momentum is boosting the index because of the heavy concentration of technology and AI companies in the index. 

So the rationale for continuing stock market rally is earnings growth and not any bubble.
 
But my understanding of this is that it is a bubble and there is catch in the so called earnings growth which is nothing but accounting jugglery. So how this is being done and when we can see that getting bust?
 
I call this “Accounting jugglery” because of the way earnings and capex are booked in the accounting books. Suppose Nvidia is selling its chips and hardware to AI companies and technology companies like Google,Microsoft, Amazon, Tesla, Spacex or OpenAI ,etc. for that matter. Now NVidia books this as revenues in its books but the user technology companies show it as Capex and so it does not show in the P&L accounts as expenses but is being booked in the balance sheet as Capex.
 
So despite suppose spending about USD 250 bn by the technology companies, it doesn’t report any expenses and interest cost artificially boosting profits and showing that earnings are growing so are the stock prices and that’s why it’s not called bubble as these are capex for future . Also companies are taking big debt for funding the capex. But the problem is uncertainty of the future earnings timeline and probability of future earnings as profits from the capex may be realized after 5 years or in more distant future or there may not be any gains from the capex but depreciation and amortization can be shown after 5 years and can be spread over many years as there is no standardization of rate of depreciation for AI capex. So investors are taking the distant future growth from the capex as certain as well as discounting today and pricing the stock on that utopian assumption as if profits are going to be realized in 1-2 years. That’s the biggest mistake by the market in my view.
 
So the next question is when this AI bubble can bust? My take is that since investors are discounting next 2 years’ future profits in today’s price. So when it won’t be realized and companies would have to depreciate the capex and also account for the debt and interest payment, it will start hurting profits and stocks would start falling and then suddenly there would be blood bath in the market. So still we may have about 2 years of irrational exuberance in AI and technology stocks before it getting busted.