There is no reason you should have to manually adjust a subtraction formula every week just because the larger number moves between columns. The solution is straightforward, and the fact that you are asking whether you are "just being lazy" tells us you already suspect the answer: you are not being lazy, you are being sensible. Any tool that forces you to redo the same logic week after week is the problem, not you.
What you need is a formula that looks at both values and returns the signed difference regardless of which column holds the larger number. In your example, where Physical Count is in column E and TBS QTY is in column F, the formula =E2-F2 works fine when E is larger, but flips to a negative when F is larger. If you want the sign to always reflect "Physical minus TBS," then that formula already does what you described, it returns a positive when Physical is higher and a negative when TBS is higher. But if your actual goal is to always show the absolute difference with a sign that indicates direction, then you need the IF function: =IF(E2>F2, E2-F2, F2-E2). That gives you a positive number every time, but you lose the sign. The better approach for your "set and forget" use case is to embrace the negative sign as meaningful data. A negative value tells you at a glance that TBS exceeded Physical, which is information you want, not an error to correct.
The deeper issue here is that traditional spreadsheets were built for static tables, not for workflows where the data structure shifts. You are doing inventory tracking, and the relationship between two columns is not fixed, sometimes one side is higher, sometimes the other. That is a normal pattern in real-world data, yet most spreadsheet tools still expect you to write formulas that assume a fixed winner. The solution is not to work around this with manual adjustments; it is to adopt a tool that understands the logic of comparison natively. AI-native spreadsheets can interpret your intent, calculate the signed difference between these two columns, no matter which is larger, and apply that logic across your entire workbook without you touching a single cell reference. You should be able to copy that workbook week to week and have the formula adapt automatically. That is not laziness. That is expecting your tool to do the work it was designed for.